Yet another question.

I think of a number, add 8 to it and the result is 14. Find the number

Leya [2.2K]

Answer:

6

Step-by-step explanation:

The equation for this would be:

n+8=14, since we are adding 8 to a number and getting 14

To solve, isolate the variable n, by subtracting 8 from both sides

n+8=14

n+8-8=14-8

n=6

The number is 6

3 0

3 years ago

Read 2 more answers

A study of the number of business lunches that executives in the insurance and banking industries claim as deductible expenses p

gizmo_the_mogwai [7]

Answer:

$t=\frac{9.1-8}{\sqrt{\frac{(1.9)^2}{40}+\frac{(2.1)^2}{50}}}}=2.604$

$p_v =2*P(t_{(88)}>2.604)=0.0108$

So the p value is a very low value and using any significance level for given $\alpha=0.05$ always $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and there is enough evidence to conclude that the two means are significantly different at 5%

Step-by-step explanation:

Data given and notation

$\bar X_{1}=9.1$ represent the mean for the sample 1

$\bar X_{2}=8$ represent the mean for the sample 2

$s_{1}=1.9$ represent the sample standard deviation for the sample 1

$s_{2}=2.1$ represent the sample standard deviation for the sample 2

$n_{1}=40$ sample size for the group 1

$n_{2}=50$ sample size for the group 2

t would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the mean are different , the system of hypothesis would be:

Null hypothesis: $\mu_{1} = \mu_{2}$

Alternative hypothesis: $\mu_{1} \neq \mu_{2}$

If we analyze the size for the samples both are higher than 30 and the population deviations are not given, so for this case is better apply a t test to compare means, and the statistic is given by:

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

t-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

We can replace in formula (1) the results obtained like this:

$t=\frac{9.1-8}{\sqrt{\frac{(1.9)^2}{40}+\frac{(2.1)^2}{50}}}}=2.604$

Statistical decision

The first step is calculate the degrees of freedom, on this case:

$df=n_{1}+n_{2}-2=40+50-2=88$

Since is a bilateral test the p value would be:

$p_v =2*P(t_{(88)}>2.604)=0.0108$

So the p value is a very low value and using any significance level for given $\alpha=0.05$ always $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and there is enough evidence to conclude that the two means are significantly different at 5%

3 0

2 years ago

The ratio of the width to the height of a window is 2:7. The width of the window is 3ft. Write and solve a proportion to find th

poizon [28]

10.5 -- 3/2=1.5 -- 7x1.5=10.5

5 0

3 years ago

Lliana rotated trapezoid WXYZ 180° about the origin.

AfilCa [17]

Answer:

The answer to the equation is W’(4, –2), X’(3, –4), Y’(1, –4), Z’(0, –2)

Step-by-step explanation:

Because its turning 180 degrees that means its turning half the way it is. and if you look on the graph the z is Z (0, 2). which if you flip it upside down it would be (0,-2)

Also i took the test! :)

6 0

3 years ago

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PLEASE HELP... Students are making necklaces of six beads for their mothers. There are

nasty-shy [4]

Answer:

Step-by-step explanation:

#1 Number of ways picking 2 from 6 = 6C2 = 15

#2 Arranging them in a circle (consider 1 pair AB)

can be done

1,5 (ABBBBB) or (5,1)

2,4 ( AABBBB) or (4,2)

3,3

1,1 (ABABAB)

all up = 7 ways

#3 = product of #1 and #2 = 15x7 = 105

3 0

1 year ago