Answer:
-2/3
Step-by-step explanation:
A rational number is a number that can be expressed by a fraction so when y add to fractions it’s a rational number.
A telephone exchange operator assumes that 9% of the phone calls are wrong numbers. If the operator is correct, 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%
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%
What is the value of y?
Enter your answer, as an exact value, in the box.
Answer:
y=4√3 units
Step-by-step explanation:
Hi there!
We are given ΔABC, which is a right triangle (m<C=90°), m<A=60°, AB=8, and BC=y
We need to find the value of y (BC)
The side AB is the hypotenuse of the (the side opposite from the right angle).
BC is a leg, which is a side that makes up the right angle.
Now, if we have a right triangle that has one of the acute angles as 60°, the side OPPOSITE from that 60° angle (in this case, BC) is equal to [tex]\frac{a\sqrt{3}}{2}[/tex], where a is the length of the hypotenuse
Since we have the hypotenuse given as 8, the length of BC (y) is [tex]\frac{8\sqrt{3}}{2}[/tex], or 4√3
so y=4√3 units
Hope this helps!
What is the value of k?
K=?
9514 1404 393
Answer:
k = 2
Step-by-step explanation:
The geometric mean theorem for the altitude tells you ...
ON = √(OL·OM)
ON² = OL·OM . . . . . square both sides
4² = 8·k . . . . . . . . substitute values
k = 16/8 = 2 . . . . divide by the coefficient of k
_____
Additional comment
The geometric mean theorem for the legs tells you ...
MN = √(MO·ML) ⇒ l = 2√5
LN = √(LO·LM) ⇒ m = 4√5
These relations come from the fact that corresponding sides of the right triangles are proportional. (All of the triangles are similar.)
Question 8
Points 3
Identify the functions whose lines are parallel.
0 3x + 2y = 45 and 8x + 4y = 135
x + y = 25 and 2x + y = 15
O 2x + 2y = 50 and 4x + 2y = 90
O 2x + 2y = 4 and 4x + 4y = 16
Answer:
2x + 2y = 4 and 4x + 4y = 16
Step-by-step explanation:
For two lines to be parallel, they must have the same slope.
To determine the correct answer to the question, we shall determine the slope of each equation in the given options to see which have the same slope. This can be obtained as follow:
1st option:
3x + 2y = 45 and 8x + 4y = 135
We shall rearrange the above equations to look like y = mx + c
NOTE: m is the slope.
3x + 2y = 45
rearrange
2y = –3x + 45
Divide both side by 2
y = –3x/2 + 45/2
Slope (m) = –3/2
8x + 4y = 135
Rearrange
4y = –8x + 135
Divide both side by 4
y = –8x/4 + 135/4
Slope (m) = –8/4 = –2
The two equation has different slopes. Thus, they are not parallel.
2nd option:
x + y = 25 and 2x + y = 15
x + y = 25
Rearrange
y = –x + 25
Slope (m) = –1
2x + y = 15
Rearrange
y = –2x + 15
Slope (m) = –2
The two equations has different slopes. Thus, they are not parallel.
3rd option:
2x + 2y = 50 and 4x + 2y = 90
2x + 2y = 50
Rearrange
2y = –2x + 50
Divide both side by 2
y = –2x/2 + 50/2
Slope (m) = –2/2 = –1
4x + 2y = 90
Rearrange
2y = –4x + 90
Divide both side by 2
y = –4x/2 + 90/2
Slope (m) = –4/2 = –2
The two equations has different slopes. Thus, they are not parallel.
4th option:
2x + 2y = 4 and 4x + 4y = 16
2x + 2y = 4
Rearrange
2y = –2x + 4
Divide both side by 2
y = –2x/2 + 4/2
Slope (m) = –2/2 = –1
4x + 4y = 16
Rearrange
4y = –4x + 16
Divide both side by 4
y = –4x/4 + 16/4
Slope (m) = –4/4 = –1
The two equations have the same slopes. Thus, they are parallel.
The width of a rectangle is 2 cm less than its length. The perimeter is 52 cm. The length is:
14 cm.
12 cm.
9 cm.
None of these choices are correct.
Answer: 14 cm
Step-by-step explanation:
Rectangle:
Length = xWidth = x - 2x + x + (x - 2) + (x - 2) = 52
2x + 2(x - 2) = 52
2x + 2x - 4 = 52
4x = 52 + 4
4x = 56
x = 14
A candy company fills a package of candy with individually wrapped pieces of candy. The number of pieces of candy per package varies because the package is sold by weight. The company wants to estimate the number of pieces per package. Inspectors randomly sample 120 packages of this candy and count the number of pieces in each package. They find that the sample mean number of pieces is 18.72. Assume the population standard deviation of .8735. What is the point estimate of number of pieces per package
Answer:
The point estimate for the number of pieces per package is of 18.72.
Step-by-step explanation:
Point estimate of a population mean:
The mean of the sample gives an estimate for the population mean.
They find that the sample mean number of pieces is 18.72.
This means that the point estimate for the number of pieces per package is of 18.72.
The proportion of brown M&M's in a milk chocolate packet is approximately 14% (Madison, 2013). Suppose a package of M&M's typically contains 52 M&M's
Answer:
7 brown M&Ms.
Step-by-step explanation:
This question is not complete, but I will assume that the final question is how many brown M&Ms will be in this package.
0.14 × 52 is our equation.
The answer is 7.28. We cannot have .28 of a brown M&M in a package (unless you count the broken ones) so there will be, on average, 7 brown M&Ms in a package.
(again, the question is incomplete, so this may not be the answer)
Melanie has D dimes and Q quarters. She has no less than $4 worth of coins altogether. Write this situation as an inequality.
Step-by-step explanation:
D(.10) + Q(.25) = 4
I think
Answer:
D(.10) + Q(.25) = 4
Step-by-step explanation:
Using law of sines please show process!!!
Let the <C=x
We know in a triangle
☆Sum of angles=180°
[tex]\\ \sf\longmapsto 51+26+x=180[/tex]
[tex]\\ \sf\longmapsto 77+x=180[/tex]
[tex]\\ \sf\longmapsto x=180-77[/tex]
[tex]\\ \sf\longmapsto x=103°[/tex]
In a pen of goats and chickens, there are 40 heads. and 130 feet How many goats and chickens are there?
Answer:
25 goat and 15 chicken
Step-by-step explanation:
Say the number of goats is G, then the number of chickens is 40 - G as there are 40 heads and each chicken and each goat has one head.
The number of feet is 130
So 2(40 - G) + 4G = 130
So 80 - 2G + 4G = 130
2G = 50
G = 25
25 goats and 15 chickens
write the volume formula beside the solid figure
Answer:
cube(v=l×l×l)
cylinder (v= πr^2h)
cone(v=1/3πr^2h)
rectangular prism (v= area of base×lenght)
pyramid (v=1/3×area of base×h)
Step-by-step explanation:
Cube:-a^3
Cuboid:-lbh
Cylinder :-pi r^2h
Cone:-1/3pi r^2h
Which expression gives the best estimate of 30 percent of 61?
The answers are below:
Hurry, please!
Answer:
it would be 1/4(60)
Step-by-step explanation:
30 percent of 61 is 18.3 and 1/4 of 60 is 15 which is closest to 18.3
If A = {x, y, z} then the number of non-empty subsets of A is ________.
a) 8 b) 5 c) 6 d) 7
Answer:
(d) 7
Step-by-step explanation:
The total number of subsets that can be derived from a set with n elements is given by;
2ⁿ
Out of these subsets, there is one empty set. Therefore, the total number of non-empty subsets is given by;
2ⁿ - 1
Given:
A = {x, y, z}
Set A has 3 elements. This means that n = 3
Therefore, the total number of subsets that can be derived from set A is
2ⁿ = 2³ = 8
One of these 8 subsets is an empty set, therefore, the total number of non-empty subsets of A is;
2ⁿ - 1 = 2³ - 1
8 - 1 = 7
This can be checked by writing all the possible subsets of A as follows;
∅
{x}
{y}
{z}
{x, y}
{y, z}
{x, z}
{x, y, z}
Removing the empty set ∅, the non-empty subsets of A are;
{x}
{y}
{z}
{x, y}
{y, z}
{x, z}
{x, y, z}
Need help on this problem
Answer:
Step-by-step explanation:
[tex]2(x-2)^2=8(7+y)\\2(x-2)^2=56+8y \Rightarrow y={1\over{8}}[2(x-2)^2-56]={1\over{4}}(x-2)^2-7\\finally\\y={1\over{4}}(x-2)^2-7\\let ~change~x~and~y\\x={1\over{4}}(y-2)^2-7\\x+7={1\over{4}}(y-2)^2\\4(x+7)=(y-2)^2\\y-2=\pm\sqrt{4(x+7)}\\\\y=2\pm\sqrt{4x+28}[/tex]
Is the random variable described discrete or continuous? The amount of rain during the next thunderstorm.
Answer:
continuous
rain does not fall in specific units like 1 inch , 2 inches etc... but 1.23456 etc..
Step-by-step explanation:
Please help me i will give you brainlest
Answer:
x = 14/3
Step-by-step explanation:
9.
The given equation is:
(x-2)+(x-3)+(x-9)=0
After opening the brackets,
x-2+x-3+x-9=0
3x+(-2-3-9) = 0
3x-14=0
x = 14/3
So, the value of x is equal to 14/3.
A bank gives you a loan of 1,500,000 Baht to buy a house. The interest rate of the loan is 0.01% per day (Using 1 year = 365 days) How much interest you pay after 10 years
Answer:
547 500
Step-by-step explanation:
Interest for 1 year:
0.01%×365=3.65 a year
3.65×10=36.5% for 10 years
36.5×1,500,000÷100=547 500
The interest paid after 10 years is 547 ,500 Baht.
What is Interest ?Interest is the amount paid or earned when a loan is taken or an investment is done respectively.
It is given that
Principal = 1,500,000 Baht
Rate = 0.01 % per day
Time period = 10 years
Interest = ?
Interest = P *R *T/100
Interest = 1500000 * 0.01 *365* 10 / 100
Interest = 547,500 Baht
Therefore the interest paid after 10 years is 547 ,500 Baht.
To know more about Interest
https://brainly.com/question/13324776
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سا (a) From the definition of derivatives determine dy÷dx if y = -2÷x
Step-by-step explanation:
Given: [tex]y = -\dfrac{2}{x}[/tex]
Derivative of a power function [tex]x^n[/tex]:
[tex]\dfrac{d}{dx}(x^n) = nx^{n-1}[/tex]
Therefore,
[tex]\dfrac{dy}{dx}=-2(-1)x^{-2} = \dfrac{2}{x^2}[/tex]
solve the following by factolisation formula
1. x(2x+1)=0
2.4xsquere-11-3x=0
1.
X = 0
2x + 1 = 0
X = 0
X = - ½ (Because we brought the numbers from one side to the other)
2.
Not sure for number 2.
in a class of 38 student,30 are good in mathematics and 22 are good in physics how many students are good in both mathematics and physics
Answer:
8 are bad in math and 16 in physics
Step-by-step explanation:
Find sin d, sin e, cos d, and cos e. Write each answer as a fraction in simplest form
Answer:
r= 17.73174
Step-by-step explanation:
calculations
Chef Amy does beginning inventory on Thursday night and finds that she has $4697 in food products in the restaurant
Throughout the week she purchases:
$668 produce
$2206 meat
$2488 dry goods
$3755 dairy
The following Thursday she does ending inventory and finds that she has $3518 in food.
She looks at her sales and finds that she made $30658 over the same 7 day period.
What is her food cost as a percentage of sales (her food cost percentage)? Please input your answer as a percentage (30%), instead of a decimal (0.3).
Answer:
Her food cost as a percentage of sales is 33.58%.
Step-by-step explanation:
Since Chef Amy does beginning inventory on Thursday night and finds that she has $ 4697 in food products in the restaurant, and throughout the week she purchases:
$ 668 produces
$ 2206 meat
$ 2488 dry goods
$ 3755 dairy
The following Thursday she does ending inventory and finds that she has $ 3518 in food.
She looks at her sales de ella and finds that she made $ 30658 over the same 7 day period.
To determine what her food cost is as a percentage of sales (her food cost percentage), the following calculation must be performed:
4,697 + 668 + 2,206 + 2,488 + 3,755 = 13,814
13,814 - 3,518 = 10,296
30,658 = 100
10,296 = X
10,296 x 100 / 30,658 = X
1,029,600 / 30,658 = X
33.58 = X
Therefore, her food cost as a percentage of sales is 33.58%.
The following figure appears in a math workbook. Students are asked to reflect the polygon across the line, then rotate it 90 degrees clockwise . Which figure shows the result of the two transformations?
Answer:
C
Step-by-step explanation:
tracing paper is your friend
Working to
(simplify y
Lisa, an experienced shipping clerk, can fill a certain order in 7 hours, Bill, a new clerk, needs 9 hours to do the
same job. Working together, how long will it take them to fill the order?
it might take 19 hours i might be wrong
Step-by-step explanation:
\int (x+1)\sqrt(2x-1)dx
Answer:
[tex]\int (x+ 1) \sqrt{2x-1} dx = \frac{1}{3}(x+1) (2x - 1)^{\frac{3}{2} } - \ \frac{1}{15}(2x-1)^{\frac{5}{2}} + C[/tex]
Step-by-step explanation:
[tex]\int (x+1)\sqrt {(2x-1)} dx\\Integrate \ using \ integration \ by\ parts \\\\u = x + 1, v'= \sqrt{2x - 1}\\\\v'= \sqrt{2x - 1}\\\\integrate \ both \ sides \\\\\int v'= \int \sqrt{2x- 1}dx\\\\v = \int ( 2x - 1)^{\frac{1}{2} } \ dx\\\\v = \frac{(2x - 1)^{\frac{1}{2} + 1}}{\frac{1}{2} + 1}} \times \frac{1}{2}\\\\v= \frac{(2x - 1)^{\frac{3}{2}}}{\frac{3}{2}} \times \frac{1}{2}\\\\v = \frac{2 \times (2x - 1)^{\frac{3}{2}}}{3} \times \frac{1}{2}\\\\v = \frac{(2x - 1)^{\frac{3}{2}}}{3}[/tex]
[tex]\int (x+1)\sqrt(2x-1)dx\\\\ = uv - \int v du[/tex]
[tex]= (x +1 ) \cdot \frac{(2x - 1)^{\frac{3}{2}}}{3} - \int \frac{(2x - 1)^{\frac{3}{2}}}{3} dx \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ [ \ u = x + 1 => du = dx \ ][/tex]
[tex]= \frac{1}{3}(x+1) (2x - 1)^{\frac{3}{2} } - \ \frac{1}{3} \int (2x - 1)^{\frac{3}{2}}} dx\\\\= \frac{1}{3}(x+1) (2x - 1)^{\frac{3}{2} } - \ \frac{1}{3} \times ( \frac{(2x-1)^{\frac{3}{2} + 1}}{\frac{3}{2} + 1}) \times \frac{1}{2}\\\\= \frac{1}{3}(x+1) (2x - 1)^{\frac{3}{2} } - \ \frac{1}{3} \times ( \frac{(2x-1)^{\frac{5}{2}}}{\frac{5}{2} }) \times \frac{1}{2}\\\\= \frac{1}{3}(x+1) (2x - 1)^{\frac{3}{2} } - \ \frac{1}{15} \times (2x-1)^{\frac{5}{2}} + C\\\\[/tex]
What is the slope of (-1,3) and (3,1)
Work Shown:
Apply the slope formula
m = (y2-y1)/(x2-x1)
m = (1-3)/(3-(-1))
m = (1-3)/(3+1)
m = -2/4
m = -1/2 is the slope
In decimal form, this converts to -0.5, though usually slopes are in fraction form.
if a x + B Y is equal to a square minus b square and b x + A Y is equal to zero find the value of x + Y
9514 1404 393
Answer:
a-b
Step-by-step explanation:
Add the two equations together:
(ax +by) +(bx +ay) = (a² -b²) +(0)
x(a +b) +y(a +b) = (a +b)(a -b)
x + y = a - b . . . . . divide by (a+b), assuming a+b ≠ 0
Omar has a gift card for $40.00 at a gift shop. Omar wants to buy a hat for himself for $13.50. For his friends, he would like to buy souvenir
bracelets, which are $3.25 each. All prices include taxes.
Which inequality can be used to solve for how many bracelets Omar can buy?
ОА.
3.25x + 13.50 S 40
OB.
3.25x + 13.50 240
Oc.
13.50x +3.25 S 40
OD.
13.50x +3.25 2 40
Answer:
A. 3.25x + 13.50 ≤ 40
The number of bracelets is x. It's a variable.
The 13.50 is a constant.
The total needs to be less than or equal to 40 because that's all the money he has.
Answer:
3.25x + 13.50 ≤ 40
Step-by-step explanation:
For this problem, you have to directly make the equation. Using the givens, it shows that he has only 40 dollars, and wants to buy only one hat for 13. 50. He wants to buy his friends braclets 3.25, but since you dont know how many friends its for, you will leave it as x.
There is only 40 dollars so you will use: ≤
The answer will be:
3.25x + 13.50 ≤ 40
Hope this helps.
You plan to conduct a survey to find what proportion of the workforce has two or more jobs. You decide on the 95% confidence level and a margin of error of 2%. A pilot survey reveals that 5 of the 50 sampled hold two or more jobs.
How many in the workforce should be interviewed to meet your requirements? (Round up your answer to the next whole number.)
Answer:
865 in the workforce should be interviewed to meet your requirements
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is given by:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
A pilot survey reveals that 5 of the 50 sampled hold two or more jobs.
This means that [tex]\pi = \frac{5}{50} = 0.1[/tex]
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
How many in the workforce should be interviewed to meet your requirements?
Margin of error of 2%, so n for which M = 0.02.
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.02 = 1.96\sqrt{\frac{0.1*0.9}{n}}[/tex]
[tex]0.02\sqrt{n} = 1.96\sqrt{0.1*0.9}[/tex]
[tex]\sqrt{n} = \frac{1.96\sqrt{0.1*0.9}}{0.02}[/tex]
[tex](\sqrt{n})^2 = (\frac{1.96\sqrt{0.1*0.9}}{0.02})^2[/tex]
[tex]n = 864.4[/tex]
Rounding up:
865 in the workforce should be interviewed to meet your requirements
HELP PLEASE!!! So for this problem is got 0.48 however I just wanted to confirm that my answer is correct. Can someone please help me if the answer is wrong and how to solve it. Thank your for your time
Answer:
ur answer is correct
A =xy
A = 1.6×0.3 = 0.48