Answer:
t = -1.862, df = 399, p > 0.05
Step-by-step explanation:
The null hypothesis is the statement which is test for its validity. The decision to accept or reject the null hypothesis is based on the test statistics value. In the given question the null hypothesis is H0 = 34. There is one sample t-test for the testing of null hypothesis. The null hypothesis will be same for each type of one sample t-test. The null hypothesis assumes that the difference between the true mean and comparison value is zero.
Give examples of two variables that have a perfect positive linear correlation and two variables that have a perfect negative linear correlation.
Answer:
answer below
Step-by-step explanation:
1. price per gallon of gasoline and total cost of gasoline
2. distance from a door and height of a wheelchair ramp
perfect positive linear relationship:
this is a relation that exists between two variables. The pearson correlation is used to check this relationship and if the relationship is 1.0 then it is established that a positive linear relationship exists
negative linear relationship
this is a relationship between variables where the pearson correlation is less than 0. if the value is -1.0 then a negative linear relatioship exists.
price per gallon of gasoline and total cost of gasoline move in the same direction so it is positive.
distance from a door and height of a wheelchair ramp are negative because they do not move in the same direction.
Which point slope form equations could be produced with the points (3,2) and (4,6)
Step-by-step explanation:
Equation of a line is y = mx + c
where
m is the slope
c is the y intercept
To find the equation of a line given two points first find the slope of the line and use the formula
y - y1 = m( x - x1) to find the Equation of the line using any of the points given
Slope of the line using points
(3,2) and (4,6) is
[tex]m = \frac{6 - 2}{4 - 3} = \frac{4}{1} = 4[/tex]
So the equation of the line using point
( 3 , 2 ) and slope 4 is
y - 2 = 4( x - 3)Hope this helps you
The top speed of this coaster is
128 mph. What is the tallest peak
of this coaster?
** Hint... convert mph into m/s.*
To convert miles per hour to meters per second divide by 2.237
128 miles per hour / 2.237 = 57.22 meters per second.
Using the first equation:
57.22 = sqrt(2 x 9.81 x h)
Remove the sqrt by raising both sides to the second power:
57.22^2 = (2 x 9.81 x h)
Simplify Both sides:
3274.1284 = 19.62h
Divide both sides by 19.62:
H = 3274.1284/ 19.62
H = 166.88 meters
A girl has 98 beads, and all but 14 were lost. how many beads did she loose?
Answer:
84 beads
Step-by-step explanation:
She had 98 beads and lost all but fourteen. So it would be 98 - 14 which would get you 84 beads that the girl has lost
what is (2y + 5)(y - 3) in simplified form using the distributive property
Answer:
[tex]\boxed{2y^{2} - y - 15}[/tex]
Step-by-step explanation:
Use the FOIL technique in order to distribute the terms properly. FOIL stands for First Terms, Outside Terms, Inside Terms, and Last Terms. In order to properly distribute, multiply the common terms based on the steps in the FOIL technique. So, in this case:
The first terms are 2y and y. The outside terms are 2y and -3. The inside terms are 5 and y.The last terms are 5 and -3.Therefore, multiply the terms:
2y and y to get 2y²2y and -3 to get -6y5 and y to get 5y5 and -3 to get -15Then, add or subtract based on the signs:
2y² - 6y + 5y - 15
Then, add like terms to finish simplifying the expression. This leaves you with 2y² - y - 15.
Answer:
2y2 – y – 15
Step-by-step explanation:
(2y + 5)(y – 3)
= 2y(y – 3) + 5(y – 3)
= 2y2 – 6y + 5y – 15
= 2y2 – y –15
evaluate -99 + 3^2•5
Answer:
= - 54
Step-by-step explanation:
- 99 + 3^2•5
- 99 + 9 × 5
- 99 + 45
= - 54
PLEASE HELPPPP
A standard I.Q. test produces normally distributed results with a mean of 100 and a standard deviation of 15 for the city of New York. Out of approximately 8,400,000 citizens, how many of these people would have I.Q.s below 67?
Answer:
approx 193200
Step-by-step explanation:
As known for normal distribution is correct the rule 95.4% of the results are situation within mean+-2*s ( where s is a standard deviation)
So the border is 100+-2*15=70 and that is approx=67.
95.4% of 84000000 citizens are= 8 400 000*0.954=8013600 persons
So the residual number of the citizens =8400000-8013600=386400 citizens
Because of the simmetry of normal distribution to find the number of the citizens that have IQ below 67 we have to divide 386400 by 2.
N=386000/2=193200
1. What is the difference between an exponential growth and exponential decay? 2. What is an example equation for expoential growth and an example equation for exponential decay?
Answer: see below
Step-by-step explanation:
The standard form of an exponential equation is: y = a(b)ˣ where
a is the initial valueb is the rateGrowth:
Exponential growth is where the final value (y) is greater than the initial value (a).
An example would be the spreading of a rumor:
You tell 1 person (a = 1) who then tells 2 people each minute (b = 2). How many people will they have spread the rumor to after 5 minutes (x = 5)?
y = 1(2)⁵
= 32
Decay:
Exponential decay is where the final value (y) is less than the initial value (a).
An example would be the decrease of bacteria in a person:
A person has 100 bacteria (a = 1) who takes a pill that is supposed to cut in half the number of bacteria each hour (b = 1/2). How many bacteria will the person have after 2 hours (x = 2)?
[tex]y=100\bigg(\dfrac{1}{2}\bigg)^2\\\\\\.\quad =100\bigg(\dfrac{1}{4}\bigg)\\\\\\.\quad = 25[/tex]
A random sample of 12 second-year university students enrolled in a business statistics course was drawn. At the course's completion, each student was asked how many hours he or she spent doing homework in statistics. The data are listed below. 20, 29, 28, 22, 26, 22, 22, 18, 23, 21, 20, 27 It is known that the population standard deviation is 7. The instructor has recommended that students devote 2 hours per week for the duration of the 12-week semester, for a total of 24 hours. Test to determine whether there is evidence at the 0.07 significance level that the average student spent less than the recommended amount of time. Fill in the requested information below.A. The value of the standardized test statistic:Note: For the next part, your answer should use interval notation. An answer of the form (−[infinity],a) is expressed (-infty, a), an answer of the form (b,[infinity]) is expressed (b, infty), and an answer of the form (−[infinity],a)∪(b,[infinity]) is expressed (-infty, a)U(b, infty). B. The rejection region for the standardized test statistic:C. The p-value isD. Your decision for the hypothesis test: A. Reject H0. B. Do Not Reject H1. C. Do Not Reject H0. D. Reject H1.
Answer:
Reject H₀.
Step-by-step explanation:
In this case, we need to test whether the average student spent less than the recommended amount of time doing homework in statistics.
The provided data is:
S = {20, 29, 28, 22, 26, 22, 22, 18, 23, 21, 20, 27}
Compute the sample mean:
[tex]\bar x=\frac{1}{n}\sum X=\frac{1}{12}\cdot [20+29+...+27]=23.167[/tex]
The population standard deviation is σ = 7.
The hypothesis for the test is:
H₀: The average student does not spent less than the recommended amount of time doing homework, i.e. μ ≥ 24.
Hₐ: The average student spent less than the recommended amount of time doing homework, i.e. μ < 24.
(A)
Compute the standardized test statistic value as follows:
[tex]z=\frac{\bar x-\mu}{\sigma/\sqrt{n}}[/tex]
[tex]=\frac{23.167-24}{7/\sqrt{12}}\\\\=-0.412[/tex]
Thus, the standardized test statistic value is -0.412.
(B)
The significance level of the test is:
α = 0.07
The critical value of z is:
z₀.₀₇ = -1.476
The rejection region is:
(-∞, -0.1476)
(C)
Compute the p-value as follows:
[tex]p-value=P(Z<-0.412)=0.34[/tex]
*Use a z-table.
Thus, the p-value is 0.34.
(D)
Since, p-value = 0.34 > α = 0.07, the null hypothesis was failed to be rejected at 7% level of significance.
Thus, the correct option is (A).
True or false? induction is a kind of thinking you use to form general ideas and rules based on mathematical formuals
Answer:
Hey there!
True. You use individuals rules, pieces of evidence, and experimentally found ideas that can be combined to form a general mathematical statement.
Let me know if this helps :)
−(−49) = −49 true or false?
How many variable terms are in the expression 3x3y + 5x2 − 4y + z + 9?
Answer:
4
Step-by-step explanation:
"4" is the number of variable terms that are in the expression 3x3y + 5x2 _ 4y + z + 9. The four variable terms in the expression are "xy", "x^2", "y" and "z". I hope that this is the answer that you were looking for and the answer has actually come to your desired help. If you need any clarification, you can always ask.
A study of the effect of television commercials on 12-year-old children measured their attention span, in seconds.
Clothes Food Toys
27 44 61
22 49 64
46 37 57
35 56 48
28 47 63
31 42 53
17 34 48
31 43 58
20 57 47
47 51
44 51
54
1. Find the values of mean and standard deviation.
2. Is there a difference in mean attention span of the children for various commercials?
3. Are there significance differences between pair of means?
Answer: Find answers in the attachment files
Step-by-step explanation:
The lines below are parallel. If the slope of the green line is -4, what is the slope of the red line?
Answer:
-4
Step-by-step explanation:
Hey there!
Well the slopes of 2 parallel lines have the same slope,
meaning if the green line has a slope of -4 then the slope of the red line has a slope of -4.
Hope this helps :)
simplify use the multiplication rule
Answer:
3
Step-by-step explanation:
[tex] \sqrt[4] {27} \cdot \sqrt[4] {3} = [/tex]
[tex] = \sqrt[4] {27 \cdot 3} [/tex]
[tex] = \sqrt[4] {3^3 \cdot 3^1} [/tex]
[tex] = \sqrt[4] {3^4} [/tex]
[tex] = 3 [/tex]
Jury Duty Three people are randomly selected from voter registration and driving records to report for jury duty. The gender of each person is noted by the county clerk.
a. Define the experiment.
b. List the simple events in S.
c. If each person is just as likely to be a man as a woman, what probability do you assign to each simple event?
d. What is the probability that only one of the three is a man?
e. What is the probability that all three are women?
Answer:
(a) The experiment defined here is a random variable that includes the selecting of 3 people from the set of voter registration and driving records.
(b) The simple events in sample space, S = (M, M, M), (M, F, M), (M, M, F), (F, M, M), (F, M, F), (F, F, M), (M, F, F), and (F, F, F).
(c) If each person is just as likely to be a man as a woman, then the probability for each of the simple event can be assigned as [tex]0.5 \times 0.5 \times 0.5 = 0.125[/tex].
(d) The probability that only one of the three is a man is 0.375.
(e) The probability that all three are women is 0.125.
Step-by-step explanation:
We are given that three people are randomly selected from voter registration and driving records to report for jury duty. The gender of each person is noted by the county clerk.
(a) The experiment defined here is a random variable that includes the selecting of 3 people from the set of voter registration and driving records.
(b) As we know that the gender of each person is noted by the county clerk, which means one is male and another female.
So, the simple events in sample space, S = (M, M, M), (M, F, M), (M, M, F), (F, M, M), (F, M, F), (F, F, M), (M, F, F), and (F, F, F).
Here, M is denoted for male and F for female.
(c) If each person is just as likely to be a man as a woman, then the probability for each of the simple event can be assigned as [tex]0.5 \times 0.5 \times 0.5 = 0.125[/tex].
Because there is 50-50 chance of selecting males or females.
(d) The probability that only one of the three is a man is given by;
The total cases in the sample space = 8
Number of cases of only one man out of three = 3
So, the required probability = [tex]\frac{3}{8}[/tex] = 0.375.
(e) The probability that all three are women is given by;
The total cases in the sample space = 8
Number of cases of all three are women = 1
So, the required probability = [tex]\frac{1}{8}[/tex] = 0.125.
PLEASE HELP ME ASAP On a test, the average score of 25 boys and 15 girls is 68 points. The average test score of the boys is 62 points. What is the average score of the girls? SHOW YOUR WORK
Answer:
74
Step-by-step explanation:
The average score of boys and girls is 68 and boys is 62
Think of it as an equation (62 + x)/2 = 68, where x is the average score of girls
First multiply each side by 2 making the equation 62 + x = 136
Now subtract each side by 62, which will make the average score for girls 74
(x = 74)
A machine that produces ball bearings has initially been set so that the true average diameter of the bearings it produces is 0.500 in. A bearing is acceptable if its diameter is within 0.004 in. of this target value. Suppose, however, that the setting has changed during the course of production, so that the bearings have normally distributed diameters with a mean 0.499 in. and standard deviation 0.002 in. What percentage of bearings will now not be acceptable
Answer:
the percentage of bearings that will not be acceptable = 7.3%
Step-by-step explanation:
Given that:
Mean = 0.499
standard deviation = 0.002
if the true average diameter of the bearings it produces is 0.500 in and bearing is acceptable if its diameter is within 0.004 in.
Then the ball bearing acceptable range = (0.500 - 0.004, 0.500 + 0.004 )
= ( 0.496 , 0.504)
If x represents the diameter of the bearing , then the probability for the z value for the random variable x with a mean and standard deviation can be computed as follows:
[tex]P(0.496\leq X \leq 0.504) = (\dfrac{0.496 - \mu}{\sigma} \leq \dfrac{X -\mu}{\sigma} \leq \dfrac{0.504 - \mu}{\sigma})[/tex]
[tex]P(0.496\leq X \leq 0.504) = (\dfrac{0.496 - 0.499}{0.002} \leq \dfrac{X -0.499}{0.002} \leq \dfrac{0.504 - 0.499}{0.002})[/tex]
[tex]P(0.496\leq X \leq 0.504) = (\dfrac{-0.003}{0.002} \leq Z \leq \dfrac{0.005}{0.002})[/tex]
[tex]P(0.496\leq X \leq 0.504) = (-1.5 \leq Z \leq 2.5)[/tex]
[tex]P(0.496\leq X \leq 0.504) = P (-1.5 \leq Z \leq 2.5)[/tex]
[tex]P(0.496\leq X \leq 0.504) = P(Z \leq 2.5) - P(Z \leq -1.5)[/tex]
From the standard normal tables
[tex]P(0.496\leq X \leq 0.504) = 0.9938-0.0668[/tex]
[tex]P(0.496\leq X \leq 0.504) = 0.927[/tex]
By applying the concept of probability of a complement , the percentage of bearings will now not be acceptable
P(not be acceptable) = 1 - P(acceptable)
P(not be acceptable) = 1 - 0.927
P(not be acceptable) = 0.073
Thus, the percentage of bearings that will not be acceptable = 7.3%
Philomena put some money in a 1-year CD that compounds interest monthly, and she made $14.06 in interest the first month. If the interest rate of the CD stays the same, how much will she make in interest the second month?
Answer:
Philomena would make more than $14.06 interest in the second month
Step-by-step explanation:
We are not told how much Philomena put initially, but what we are told is that she has more now as she has been making interests.
This means that if the percent interest remains the same, the amount will definitely have to be more.
For example, let's say we had $10 and we had 10% interest that means we now add $1 to make $11. Since we now have $11, 10 percent of that is $1.1. so now we have $11 + $1.1 = $12.1 which is more than $11.
Thus,Philomena would make more than $14.06 interest in the second month.
Answer:
More than 14.06
Step-by-step explanation:
apesex
Suppose 55 percent of the customers at Pizza Palooza order a square pizza, 72 percent order a soft drink, and 48 percent order both a square pizza and a soft drink. Is ordering a soft drink independent of ordering a square pizza?
Answer: No, the orders are not independent.
Step-by-step explanation:
If event 1 has some possible outcomes, suppose that we choose a given outcome 1 with a probability P1, and event 2, also with different possible outcomes, we can select an outcome 2, that has a probability P2, and the two events are independent (meaning that the outcome in event 1 does not affect the outcome in event 2, and vice versa)
Then the probability of outcome 1 and outcome 2 happening at the same time is equal to the product of their individual probabilities.
P = P1*P2.
In this case, event 1 is the selection of the pizza, and outcome 1 is the selection of the square pizza, with a probability of 55%.
Event 2 is the selection of the drink, outcome 2 is the order of a soft drink, with a probability of 72%.
If those two events were independent, then the probability that a customer orders a square pizza and a soft drink would be:
P = 0.55*0.72 = 0.396 (or 39.6%)
But we know that the actual probability is 48%.
So this is larger, which means that the outcomes are not independent.
Solve for x -3x-3=-3(x+1)
Step-by-step explanation:
[tex] - 3x - 3 = - 3(x + 1) \\ - 3x - 3 = - 3x - 3 \\ - 3x + 3x = - 3 + 3 \\ 0 = 0[/tex]
Step 1: Use 3 to open the bracket
Step 2 : Collect like terms and simplify
Answer = 0
During the school year, there were 315 total points scored between basketball, soccer, baseball, and football. The baseball team scored 55 points. The soccer team scored twice as much as the baseball team. The football team scored 0.5 more than 1.5 times as much as the baseball team. How many points did the basketball team score?
Answer:
67.5p.
Step-by-step explanation:
315p in total.
- Baseball has 55p.
- Soccer teams points = 55x2 = 110p.
- Football team points = 110 x 0.5 = 55 x 1.5 = 82.5p.
So then you just do 315p - 82.5p - 55p - 110p = 67.5p
Verify the identity. cot x / 1 + csc x = csc x - 1 / cot x
Step-by-step explanation:
cot x / (1 + csc x)
Multiply by conjugate:
cot x / (1 + csc x) × (1 − csc x) / (1 − csc x)
Distribute the denominator:
cot x (1 − csc x) / (1 − csc²x)
Use Pythagorean identity:
cot x (1 − csc x) / (-cot²x)
Divide:
(csc x − 1) / cot x
A data set lists earthquake depths. The summary statistics are
nequals=400400,
x overbarxequals=6.866.86
km,
sequals=4.374.37
km. Use a
0.010.01
significance level to test the claim of a seismologist that these earthquakes are from a population with a mean equal to
6.006.00.
Assume that a simple random sample has been selected. Identify the null and alternative hypotheses, test statistic, P-value, and state the final conclusion that addresses the original claim.
What are the null and alternative hypotheses?
A.
Upper H 0H0:
muμequals=5.005.00
km
Upper H 1H1:
muμnot equals≠5.005.00
km
B.
Upper H 0H0:
muμnot equals≠5.005.00
km
Upper H 1H1:
muμequals=5.005.00
km
C.
Upper H 0H0:
muμequals=5.005.00
km
Upper H 1H1:
muμgreater than>5.005.00
km
D.
Upper H 0H0:
muμequals=5.005.00
km
Upper H 1H1:
muμless than<5.005.00
km
Determine the test statistic.
(Round to two decimal places as needed.)
Determine the P-value.
(Round to three decimal places as needed.)
State the final conclusion that addresses the original claim.
Fail to reject
Upper H 0H0.
There is
evidence to conclude that the original claim that the mean of the population of earthquake depths is
5.005.00
km
Answer:
Step-by-step explanation:
The summary of the given statistics data include:
sample size n = 400
sample mean [tex]\overline x[/tex] = 6.86
standard deviation = 4.37
Level of significance ∝ = 0.01
Population Mean [tex]\mu[/tex] = 6.00
Assume that a simple random sample has been selected. Identify the null and alternative hypotheses, test statistic, P-value, and state the final conclusion that addresses the original claim.
To start with the hypothesis;
The null and the alternative hypothesis can be computed as :
[tex]H_o: \mu = 6.00 \\ \\ H_1 : \mu \neq 6.00[/tex]
The test statistics for this two tailed test can be computed as:
[tex]z= \dfrac{\overline x - \mu}{\dfrac{\sigma}{\sqrt {n}}}[/tex]
[tex]z= \dfrac{6.86 - 6.00}{\dfrac{4.37}{\sqrt {400}}}[/tex]
[tex]z= \dfrac{0.86}{\dfrac{4.37}{20}}[/tex]
z = 3.936
degree of freedom = n - 1
degree of freedom = 400 - 1
degree of freedom = 399
At the level of significance ∝ = 0.01
P -value = 2 × (z < 3.936) since it is a two tailed test
P -value = 2 × ( 1 - P(z ≤ 3.936)
P -value = 2 × ( 1 -0.9999)
P -value = 2 × ( 0.0001)
P -value = 0.0002
Since the P-value is less than level of significance , we reject [tex]H_o[/tex] at level of significance 0.01
Conclusion: There is sufficient evidence to conclude that the original claim that the mean of the population of earthquake depths is 5.00 km.
8) The perimeter of a rectangle is 20x2 + xy - 7y2 and one of it's sides is
7x2 - xy. Find the other side.
Answer:
3x^2 + 3xy/2 - 7xy^2/2
Step-by-step explanation:
So we know the perimeter is 20x^2 + xy - 7y^2,
To find any perimeter you need 2l + 2w = P so,
One of the sides is 7x^2 - xy
First plug in the values,
2(7x^2-xy) + 2w = 20x^2 + xy - 7y^2
Multiply,
14x^2-2xy + 2w = 20x^2 + xy - 7y^2
Subtract,
14x^2 - 2xy - 14x^2 + 2xy + 2w = 20x^2 + xy - 7y^2 - 14x^2 + 2xy
2w = 6x^2 + 3xy - 7y^2
w = 3x^2 + 3xy/2 - 7xy^2/2
Finding the perimeter or area of a rectangle given one of th
The length of a rectangle six times its width.
If the area of the rectangle is 150 cm”, find its perimeter.
Answer:
The answer is 70cmStep-by-step explanation:
Perimeter of a rectangle = 2l + 2w
Area of a rectangle = l × w
where
l is the length
w is the width
From the question
The length of a rectangle six times its width which is written as
l = 6w
Area = 150cm²
Substitute these values into the formula for finding the area
That's
150 = 6w²
Divide both sides by 6
w² = 25
Find the square root of both sides
width = 5cm
Substitute this value into l = 6w
That's
l = 6(5)
length = 30cm
So the perimeter of the rectangle is
2(30) + 2(5)
= 60 + 10
= 70cmHope this helps you
A recipe calls for 2 tablespoons of sugar for every 7 tablespoons of flour. If you plan on tripling the recipe what is the ratio of
sugar to flour?
-0)
A)
2 to 7
B)
2 to 21
5 to 10
DY
5 to 7
Answer:
It is still 2 to 7
Step-by-step explanation:
It is still 2 to 7 because if you triple the recipe, it will become 6 to 21 which still simplifies to 2 to 7.
A baking scale measures mass to the tenth of a gram, up to 650 grams. A cup of flour is placed on the scale and results in a measure of 121.8 grams. Which of the following statements is not true?
a.The exact mass of the cup of flour must be between 121.7 and 121.9 grams.
b.The cup of flour has a mass of exactly 121.8 grams.
c.Given the limitations of the scale, the measurement has an appropriate level of accuracy.
d.To the nearest gram, the cup of flour has a mass of 122 grams.
Answer
Is it C I may have done my math wrong lol
Step-by-step explanation:
17. In figure, BAC -859, CA = CB and BD - CD. Find the measure of ZX, Zy and Zz. Give
reasons to support your answer.
A
85°
ب
B
H
V
Answer:
x = 10°, y = 10° and z = 160°
Step-by-step explanation:
Given : m∠BAC = 85°
CA ≅ CB and BD ≅ CD
In the given ΔABC,
Since, CA ≅ CB
Angles opposite to these equal sides will be equal in measure.
m∠BAC ≅ m∠ABC ≅ 85°
Since, sum of interior angles of a triangle = 180°
m∠BAC + m∠ABC + m∠BCA = 180°
85° + 85° + m∠BCA = 180°
m∠BCA = 180° - 170°
m∠BCA = 10°
x = 10°
In ΔBDC,
Since, BD ≅ DC [Given]
Opposite angles to these equal sides will be equal in measure.
Therefore, x° = z° = 10°
Since, x° + y° + z° = 180°
10° + y° + 10° = 180°
y = 180 - 20°
y = 160°
We have to accept or reject a large shipment of items. For quality control purposes, we collect a sample of 200 items and find 24 defective items. Construct a 95% percent confidence interval for the proportion of defective items in the whole shipment.
Answer:
A 95% confidence for the population proportion of defective items in the whole shipment is [0.075, 0.165] .
Step-by-step explanation:
We are given that for quality control purposes, we collect a sample of 200 items and find 24 defective items.
Firstly, the pivotal quantity for finding the confidence interval for the population proportion is given by;
P.Q. = [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ~ N(0,1)
where, [tex]\hat p[/tex] = sample proportion of defective items = [tex]\frac{24}{200}[/tex] = 0.12
n = sample of items = 200
p = population proportion of defective items
Here for constructing a 95% confidence interval we have used a One-sample z-test statistics for proportions.
So, 95% confidence interval for the population proportion, p is ;
P(-1.96 < N(0,1) < 1.96) = 0.95 {As the critical value of z at 2.5% level
of significance are -1.96 & 1.96}
P(-1.96 < [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < 1.96) = 0.95
P( [tex]-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < [tex]{\hat p-p}[/tex] < [tex]1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.95
P( [tex]\hat p-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < p < [tex]\hat p+1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.95
95% confidence interval for p = [ [tex]\hat p-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] , [tex]\hat p+1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ]
= [ [tex]0.12-1.96 \times {\sqrt{\frac{0.12(1-0.12)}{200} } }[/tex] , [tex]0.12+1.96 \times {\sqrt{\frac{0.12(1-0.12)}{200} } }[/tex] ]
= [0.075, 0.165]
Therefore, a 95% confidence for the population proportion of defective items in the whole shipment is [0.075, 0.165] .
