Thproduct of 12 and a number is 7

Alex73 [517]

Answer: I think it would be 4a(a−2b squared)

7 0

2 years ago

Consider the following hypothesis test: H0: LaTeX: \mu_1-\mu_2=0μ 1 − μ 2 = 0 Ha: LaTeX: \mu_1-\mu_2\ne0μ 1 − μ 2 ≠ 0 The follow

Pavel [41]

Answer:

$z=\frac{104-\bar 106}{\sqrt{\frac{8.4^2}{80}+\frac{7.6^2}{70}}}}=-1.53$

Step-by-step explanation:

Data given and notation

$\bar X_{1}=104$ represent the mean for the sample 1

$\bar X_{2}=106$ represent the mean for the sample 2

$\sigma_{1} =8.4$ represent the population standard deviation for the sample 1

$\sigma_{2}=7.6$ represent the population standard deviation for the sample 2

$n_{1}=80$ sample size for the group 1

$n_{2}=70$ sample size for the group 2

z would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the means for the two groups are the same, the system of hypothesis would be:

H0: $\mu_{1}-\mu_{2} =0$

H1: $\mu_{1} -\mu_{2} \neq 0$

If we analyze the size for the samples both are greater than 30 and we know the population deviations so for this case is better apply a z test to compare means, and the statistic is given by:

$z=\frac{\bar X_{1}-\bar X_{2}}{\sqrt{\frac{\sigma^2_{1}}{n_{1}}+\frac{\sigma^2_{2}}{n_{2}}}}$ (1)

z-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

Calculate the statistic

First we need to calculate the mean and deviation for each sample, after apply the formulas (2) and (3) we got the following results:

And with this we can replace in formula (1) like this:

$z=\frac{104-\bar 106}{\sqrt{\frac{8.4^2}{80}+\frac{7.6^2}{70}}}}=-1.53$

7 0

3 years ago

you buy two rolls of wrapping paper. each roll has the same lateral surface area. what is the diameter of roll B?

Sonbull [250]

I saw the image that should have been posted with this word problem.

The rolls of wrapping paper is cylindrical in shape.

Roll A : length = 30 inches ; diameter = 3 inches
Roll B : length = 24 inches ; diameter = unknown

Lateral surface area = 2 π r h

Lateral Surface area of Roll A = Lateral Surface area of Roll B
2 * 3.14 * 1.5in * 30in = 2 * 3.14 * r * 24 in
282.60 in² = 150.72 in * r
282.60 in² / 150.72 in = r
1.875 in = r

diameter is 2 times the radius = 1.875 in * 2 = 3.75 inches

The diameter of Roll B is 3.75 inches.

4 0

3 years ago

$375, 319

frutty [35]

Answer:

need a answer

Step-by-step explanation:

7 0

3 years ago

Write the equation of the line that passes through the point ( -6 , 2 ) and is parallel to the line y = 1/2x + 4.

SashulF [63]

Parallel lines need the same slope, and for y = 1/2x + 4, it is 1/2.

Let's solve for b.

2 = 1/2(-6) + b
2 = -3 + b
Add 3 on both sides.
5 = b

y = 1/2x + 5

8 0

3 years ago