Please help me thanks please

GalinKa [24]

Complementary angles add up to 90 degrees.

Which means.. the equation is
8x-23+7x-7=90
Combine like terms you should get
15x-30=90
Add 30 on both sides
15x=120
Divide 15 x=8
Plug in 8 to (8x-23)
8(8)=64-23=41
m

8 0

3 years ago

Twenty years ago, entering male high school students of Central High could do an average of 24 pushups in 60 seconds. To see whe

alexira [117]

Answer:

a) If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, so we can't conclude that the true mean is still equal to 24 at 5% of significance.

b) Power =0.48994+0.0000501=0.490

Step-by-step explanation:

Part a

Data given and notation

$\bar X=22.5$ represent the sample mean

$s=3.1$ represent the sample standard deviation

$n=36$ sample size

$\mu_o =68$ represent the value that we want to test

$\alpha=0.05$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is still equal to 24, the system of hypothesis would be:

Null hypothesis: $\mu = 24$

Alternative hypothesis: $\mu \neq 24$

If we analyze the size for the sample is > 30 but we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{22.5-24}{\frac{3.1}{\sqrt{36}}}=-2.903$

P-value

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

$df=n-1=36-1=35$

Since is a bilateral test the p value would be:

$p_v =2*P(t_{(35)}$

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, so we can't conclude that the true mean is still equal to 24 at 5% of significance.

Part b

The Power of a test is the probability of rejecting the null hypothesis when, in the reality, it is false.

For this case the power of the test would be:

P(reject null hypothesis| $\mu=23$ )