Answer:
0.0264 = 2.64% probability that the proportion of wrong numbers in a sample of 448 phone calls would differ from the population proportion by more than 3%
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
A telephone exchange operator assumes that 9% of the phone calls are wrong numbers.
This means that [tex]p = 0.09[/tex]
Sample of 448
This means that [tex]n = 448[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.09[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.09*0.91}{448}} = 0.0135[/tex]
What is the probability that the proportion of wrong numbers in a sample of 448 phone calls would differ from the population proportion by more than 3%?
More than 9% + 3% = 12 or less than 9% - 3% = 6%. Since the normal distribution is symmetric, these probabilities are the same, so we find one of them and multiply by 2.
Probability it is less than 6%
P-value of Z when X = 0.06. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.06 - 0.09}{0.0135}[/tex]
[tex]Z = -2.22[/tex]
[tex]Z = -2.22[/tex] has a p-value of 0.0132
2*0.0132 = 0.0264
0.0264 = 2.64% probability that the proportion of wrong numbers in a sample of 448 phone calls would differ from the population proportion by more than 3%
A sample of 25 one-year-old girls had a mean weight of 24.1 pounds with a standard deviation of pounds. Assume that the population of weights is normally distributed. A pediatrician claims that the standard deviation of the weights of one-year-old girls is less than pounds. Do the data provide convincing evidence that the pediatrician's claim is true
Answer:
Paedtricians claim isn't true.
Step-by-step explanation:
The hypothesis :
H0 : σ = 7
H0 : σ > 7
The test statistic ; χ² :
χ² = [(n - 1) * s²] ÷ σ²
n = 25 ; s = 4.3, σ = 7
χ² = [(25 - 1) * 4.3²] ÷ 7²
χ² = [(24 * 4.3²] ÷ 49
χ² = 443.76 / 49
χ² = 9.056
At α = 0.01 ; critical value = 42.980
Since critical value > test statistic, we fail to reject the null, H0.
SOMEONE HELP ASAP PLES NO EXPLANATOIN NEEDED PLS LEAVE UR ANSWER AS TEXT (SOME TIMES I CAN'T SEE IMAGES) THANK YOU SO MUCH!!!
Answer:
i cant see the image
Step-by-step explanation:
Meghan sells advertisements for a radio station. Each 30 second ad costs $20 per play, and each 60 second ad
costs $35 per play. Meghan sold 12 ads for $315. She wrote the system below letting x represent the number of 30
second ads and y represent the number of 60 second ads.
X+ y = 12
20x+35y = 315
What is the solution to the system of equations?
Need answers ASAP!!!!
Answer:
usai964s46s694s4o6s64694s946649s469 opps
Answer:
[tex](x,y)=(7,5)[/tex]
Step-by-step explanation:
Megan's equation will be:
[tex]20x+35y=315[/tex]
[tex]x+y=12[/tex]
Substitute [tex]x=12-y[/tex] in the first equation:
[tex]20(12-y)+35y=315[/tex]
[tex]15y=75[/tex]
[tex]y=75/15[/tex]
[tex]y=5[/tex]
Find x:
[tex]x=12-5[/tex]
[tex]x=7[/tex]
Where x and y represent 30-second and 60-second ads sold, we find that Meghan's sales were:
[tex](x,y)=(7,5)[/tex]
hope this helps....
Tessa conducts an experiment and obtains results that are statistically significant. What is meant by "statistically significant"? O It means that Tessa used a large sample size. O It means that the results that Tessa obtained are too unusual to be explained by chance alone. It means that Tessa's experiment was not biased. O It means that the individuals in the experiment were randomly assigned to the treatment groups. earch 0 so DOLL
9514 1404 393
Answer:
(b) It means that the results that Tessa obtained are too unusual to be explained by chance alone
Step-by-step explanation:
The test for statistical significance is a comparison of the result to the probability that it occurred by chance. The probability of a chance occurrence is usually set at 1% or 5%. The lower the percentage, the less likely a chance occurrence is, and the more difficult showing statistical significance becomes.
which of the following function shows the absolute value parent function FX=lxl shifted up
Answer:
The answer is C.
as for C . the value of f(x) increases by 7 and so the graph goes up by units 7.
OR
g(x) = |x| + 7
we know that |x| is f(x), so :-
g(x) = f(x) + 7
and since f(x) is plot on y- axis the graph climbs the y axis by 7 units
*The graph shifts right or left for the other functions*
circle A has a center of (2,3) and a radius of 5 and circle B has a center of (1,4) and a radius of 10. What steps will help show that circle A is similar to circle B
Answer:
12
Step-by-step explanation:
Thomas Supply Company Inc. is a distributor of gas-powered generators. As with any business, the length of time customers take to pay their invoices is important. Listed below, arranged from smallest to largest, is the time, in days, for a sample of The Thomas Supply Company Inc. invoices.
13 13 13 20 26 29 32 33 34 34 35 35 36 37 38
41 41 41 45 46 47 47 48 52 54 55 56 62 67 82
(Round your answers to 2 decimal places.)
a. Determine the first and third quartiles.
Q1 =
Q3 =
b. Determine the second decile and the eighth decile.
D2 =
D8 =
c. Determine the 67th per
Answer:
Q1 = 32.5
Q3 = 50
D2 = 29
D8 = 52
67th percentile = 46.5
Step-by-step explanation:
Given the ordered data:
13, 13, 13, 20, 26, 29, 32, 33, 34, 34, 35, 35, 36, 37, 38, 41, 41, 41, 45, 46, 47, 47, 48, 52, 54, 55, 56, 62, 67, 82
The first quartile :
Q1 = 1/4(n+1)th term
n = sample size = 30
Q1 = 1/4(31) = 7.75 = (7th + 8th) / 2 = (32+33) / 2 = 32.5
Q3 = 3/4(n+1)th term
n = sample size = 30
Q3 = 3/4(31) = 23.25 = (23rd + 24th) / 2 = (48+52) / 2 = 50
D2 = 2nd decile
2 * 10% = 20%
20% * n
0.2 * 30 = 6th = 29
D8 = 8th decile
8 * 10% = 80%
80% * 30 = 24th = 52
67th percentile :
0.67 * 30 = 20.1 th
(20th + 21th) / 2
(46 + 47) / 2
= 46.5
Show all the steps to solve the following
942.6 - 19.734
Answer:
922.868
Step-by-step explanation:
1. Thousandth place of 942.6002. Subtracting[tex]942.600-19.732=922.868[/tex]
Find the range of the data.
Scores: 81, 79, 80, 88, 72, 96, 86, 73, 79, 88
Answer:
24
Step-by-step explanation:
To find the range, you must subtract the lowest value from the highest value in the data set. If you organize the set from least to greatest, 72 is the lowest, and 96 is the highest.
So, 96 - 72 = 24, which is the range.
A school contains 140 boys and 160 girls. what is the ratio of boys to girls?
I need full working out please
Answer:
7 : 8
Step-by-step explanation:
that is the procedure above
At a local university the students have been overdosing on caffeine to help them study for exams. However, many students have been getting quite sick from taking too much coffee and cola.
A. How many cups of coffee would be too much and at the dangerous level (3.00 g)? You know that coffee contains 21.5 mg caffeince per ounce and a cup is 8 oz.
B. How many cans of cola would be too much and at the dangerous level? You know that cola contains 4.20 mg per ounce and a soft drink can contain 12.0 oz.
Answer:
A) Hence, the number of coffee cups that are risky = 17.4 Cups.
B) Here, the number of coffee cups that are risky = 59.5 Colas.
Step-by-step explanation:
A)
In 1 cup coffee =[tex]8\times21.5mg= 172.0 mg[/tex]
Hence one cup of coffee contains 172 mg of caffeine. The risky level is 3000mg.
Therefore, the number of coffee cups that are risky
[tex]= 3000/172\\ \\=17.4 cups[/tex]
Here, the number of coffee cups that are risky = 17.4 cups.
B)
[tex]1 cola=12\times4.2mg\\\\ = 50.4mg / day[/tex]
Hence, one can cola contains 50.4 mg of caffeine.
The dangerous level is 3000 mg.
Therefore, the number of cola cans that are risky [tex]=3000/50.4= 59.5[/tex] cola is risky.
What is the y-intercept of the graph of y = 2.5x? a. 2.5 c. 0 b. 1 d. -1
Answer:
answer is C
Step-by-step explanation:
General equation of a line is expressed as shown:
y = mx+c where;
m is the slope or gradient of the line
c is the intercept of the line
Given the equation of the line graph as y =2.5x
Comparing the given equation with the general equation, it is seen that m = 2.5 and c = 0 (since there is no value for the intercept)
Based on the explanation, the y-intercept of the graph is therefore 0
Answer:
B
Step-by-step explanation:
To find the x-intercept, substitute in
0 for y and solve for x
To find the y-intercept, substitute in 0 for x and solve for y
x-intercept(s): None
y-intercept(s): (0,1)
Helppp me with this ,I will mark brainlest
Which simplified fraction is equal to 0.53? Need answers now plz
Answer:
8/15
Step-by-step explanation:
Answer:
8/15
Step-by-step explanation:
when you divide 8/15 its 0.53
At one point in history, the NBA finals required that one of the two teams win at least three of five games in order to win the Championship. If one team wins the first two games, what is the probability that the same team wins the Championship, assuming that the two teams are well matched and each team is equally likely to win each game
Answer:
50% i believe
Step-by-step explanation:
because in every scenario theres 2 teams and if they are well matched it be half and half on every game assuming they're the same level of comp
What does y equal in the solution of the system of equations below? 5y-3x-4z=22 2z-2x=-6 2z+3x=-6
9514 1404 393
Answer:
y = 2
Step-by-step explanation:
Subtracting the second equation from the third gives ...
(2z +3x) -(2z -2x) = (-6) -(-6)
5x = 0
x = 0
Using this in the third equation, we have ...
2z +0 = -6
z = -3
And substituting these values into the first equation, we have ...
5y -3(0) -4(-3) = 22
5y = 10 . . . . . subtract 12
y = 2
__
The solution to the system is (x, y, z) = (0, 2, -3).
If a line is equation 5 x + 6 Y is equal to 2 k together with the coronavirus access from a triangle of area 135 square unit.find the value of k.
Answer:
hdhdkdbddkdgsjshzcssjsn
$2900 at 13% for 30 years. i need simple interest and compounding interest
Answer:
Step-by-step explanation:
simple:
2900(1+.13*30)=14210
Compounding
[tex]2900(1+.13)^{30}=113436.1041[/tex]
Answer:
113436.1041
Step-by-step explanation:
2900 ( 1 +0.13 ) ^ 30
Formula : amount ( 1 + percentage ) ^ years
Private nonprofit four-year colleges charge, on average, $26,208 per year in tuition and fees. The standard deviation is $7,040. Assume the distribution is normal. Let X be the cost for a randomly selected college. Round all answers to 4 decimal places where possible.
a. What is the distribution of X? X ~ N(
26208
Correct,
7040
Correct)
b. Find the probability that a randomly selected Private nonprofit four-year college will cost less than 22,924 per year.
c. Find the 60th percentile for this distribution. $
(Round to the nearest dollar.)
Answer:
#########
Step-by-step explanation:
How much fabric is needed to make a tent in the shape of a triangular prism with the following measures?
Answer:
The fabric needs 196.4 ft²
Step-by-step explanation:
∵ The tent formed formed from 4 faces
two equilateral triangles with side length 7 ft
two rectangles with dimensions 11 ft and 7 ft
∵ Area equilateral Δ = 1/4 S²√3
∵ Area rectangle = L × W
∴ The area of the prism = 2 × 1/4 × (7)²√3 + 2 × 7 × 11
= 196.4 ft²
Note:
If you find the area of the triangle by the rule 1/2 × base × height
∴ Area Δ = 1/2 × (7) × 6 = 21 ft²
∴ Area tent = 2 × 21 + 2 × 77 = 196 ft²
Two answer very closed
Answer:
273 ft^2 (apparently you have to cover the ground)
Step-by-step explanation:
For P = {5, 12, 13, 14), Q = {2, 7, 11), and R = {4, 7, 8, 11}, find PU (Q n R).
Answer:
(5 7 11 12 13 14)
Step-by-step explanation:
Q inter R = 7 and 11
So the union between p and 7 and 11 is the answer above
How would 0.42 be shown as a percent?
A. 0.42%
B. 4%
C. 4.2%
D. 42%
Answer:
42%
Step-by-step explanation:
to find percentages, you move the decimal point twice to the right
5. Lisa has a cubed-shaped box with a
volume of 512 cm. If Lisa fills the box
with 1-cubic centimeter blocks, how
many blocks make up each layer?
Answer:
64
Step-by-step explanation:
[tex]\sqrt[3]{512} = 8\\8x8 = 64[/tex]
The diagram shows triangle ABC.
С
Work out the sizes of angles x, y and z.
40°
110°
х
Z
A
В
Answer:
x=70
y=30
z=20
Step-by-step explanation:
x=180-110 (angles on a straight line)
y=180-110-40 (angle sum of triangle)
z= 180-90-70 (angle sum of triangle)
Answer:
x=70°
y=30°
z=20°
Step-by-step explanation:
x=180°-110°(anlges on a straight line)
x=70°
y+110°+40°=180°(sum of angles of triangle)
y+150°=180°
y=180°-150°
y=30°
z+x+90°=180°(sum of angles of triangle)
z+70°+90°=180°
z+160°=180°
z=180°-160°
z=20°
Suppose that you are thinking about buying a car and have narrowed down your choices to two options.
The new-car option: The new car costs $25,000 and can be financed with a four-year loan at 6.12%.
The used-car option: A three-year old model of the same car costs $17,000 and can be financed with a three-year loan at 7.72%.
=||)
[1-(2-4) 11
What is the difference in monthly payments between financing the new car and financing the used car? Use PMT
The difference in monthly payments between financing the new car and financing the used car is $
(Round to the nearest cent as needed.)
Answer:
sjsjsuduhr r ki snsbtsuwi 3 38yv4r djvs
2) There are 40 boys and 60 girls in a class of students. What is the ratio of girls to students
Answer:
60:100, 6/10, 3/5, 6 to 10, etc.
Step-by-step explanation:
You take the number of girls over total students which is boys + girls. Since there's 40 boys and 60 girls, it's 60 girls to 100 students which can be written in several ways.
Answer:
60:100 / 3:5
Step-by-step explanation:
You first add the total number of students which is (40boys + 60girls) which gives us 100 students.
Then arrange the ratio of girls to students as per the question that is 60:100, reduce it to its lowest term that is dividing the ratio by 20, and finally got 3:5
Joe bikes at the speed of 30 km/h from his home toward his work. If Joe's wife leaves home 5 mins later by car, how fast should she drive in order to overtake him in 10 minutes.
Answer:
Joe's wife must drive at a rate of 45km/hour.
Step-by-step explanation:
We are given that Joe leaves home and bikes at a speed of 30km/hour. Joe's wife leaves home five minutes later by car, and we want to determine her speed in order for her to catch up to Joe in 10 minutes.
Since Joe bikes at a speed of 30km/hour, he bikes at the equivalent rate of 0.5km/min.
Then after five minutes, when his wife leaves, Joe is 5(0.5) or 2.5 km from the house. He will still be traveling at a rate of 0.5km/min, so his distance from the house can be given by:
[tex]2.5+0.5t[/tex]
Where t represents the time in minutes after his wife left the house.
And since we want to catch up in 10 minutes, Joe's distance from the house 10 minutes after his wife left will be:
[tex]2.5+0.5(10)=7.5\text{ km}[/tex]
Let s represent the wife's speed in km/min. So, her speed times 10 minutes must total 7.5 km:
[tex]10s=7.5[/tex]
Solve for s:
[tex]\displaystye s=0.75\text{ km/min}[/tex]
Thus, Joe's wife must drive at a rate of 0.75km/min, or 45km/hour.
Please HELP!
How many pairs (A, B) are there where A and B are subsets of {1, 2, 3, 4, 5, 6, 7, 8} and A ∩ B has exactly two elements?
Answer:
There are 256 pairs in all.
PLEASE HELPPP ASAP!!! I tried all sorts of equations but no correct answer! Not sure how to approach this problem.
Answer:
[tex]44[/tex]
Step-by-step explanation:
The dimensions of the garden is 12 by 8. If we have a walkway that surrounds the garden, the dimensions of the walkway is 2. Since it surrounds the rectangle all sides add 2 to each of the dimensions so now the dimensions of the garden and walkway is 14×10.
The area of the garden is 96 square ft.
The area of the garden and walkway is 140 so let subtract the area of the garden from the total area of both the garden and walkway.
[tex]140 - 96 = 44[/tex]
The area is 44.
Answer:
120 square feet
Step-by-step explanation:
(8+2*2)
(18+2*2) - 8*18 = 120 square feet.
Keisha borrowed $400 from a bank for 5 years and was charged simple interest. The total interest that she paid on the loan was $120. As a percentage, what was the annual interest rate of her loan?
Answer:
6%
Step-by-step explanation:
Answer:
you need to divide 120 by 5
Step-by-step explanation:
the percentage is 16.6 and it goes on that is for 1 year
