Mathematics, 23.04.2020 02:17 zzzio1866

Researchers collected a simple random sample of the times that 81 college students required to earn their bachelor's degrees. This sample has a mean of 4.8 years and a standard deviation of 2.2 years. Use a 0.05 significance level to test the claim that the mean time for all college students is greater than 4.5 years.

Answers: 2

Show answers

Answers

Answer from: laylay7383

$t=\frac{4.8-4.5}{\frac{2.2}{\sqrt{81}}}=1.227$

$p_v =P(t_{(80)}1.227)=0.1117$

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the true mean is higher than 4,5 years at 1% of signficance.

Step-by-step explanation:

Data given and notation

$\bar X=4.8$ represent the sample mean

s=2.2 represent the sample standard deviation

n=81 sample size

$\mu_o =4.5$ 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 higher than 4.5, the system of hypothesis would be:

Null hypothesis: $\mu \leq 4.5$

Alternative hypothesis: $\mu 4.5$

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:

$t=\frac{4.8-4.5}{\frac{2.2}{\sqrt{81}}}=1.227$

P-value

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

df=n-1=81-1=80

Since is a one side test the p value would be:

$p_v =P(t_{(80)}1.227)=0.1117$

Conclusion

Answer from: Quest

yor answer is 7/6 times 5

step-by-step explanation:

Which of the following products is equivalent to the quotient 1 1/6 • 1/5

Answer from: Quest

the solution is the point $(1,-3)$

step-by-step explanation:

we have

$3x-y=6$ > equation a

$y=x-4$ > equation b

adds equation a and equation b

$3x-y=6\\y=x--y+y=6+x-4\\3x=2+x\\3x-x=2\\2x=2\\x=1$

substitute the value of x in equation b to find the value of y

$y=(1)-4=-3$

the solution is the point $(1,-3)$

Another question on Mathematics

Mathematics, 21.06.2019 16:30

Asequence {an} is defined recursively, with a1 = 1, a2 = 2 and, for n > 2, an = an-1 an-2 . find the term a241

Answers: 2

Answer

Mathematics, 22.06.2019 05:00

The limit in 2008 for fica tax was 102,000. so if an individual makes $314,000 in one year, how much in "continuing" medicare tax will they have to pay? (medicare tax is 1.4% for individuals and 2.9% for the self-employed.) a: 2,968.00 b: 4,396.00 c: 6,148.00 d: 9,106.00

Answers: 2

Answer

Mathematics, 22.06.2019 06:00

If twice a number is at least three less than four times the number, which of the following are true? let n represent the number.

Answers: 1

Answer

Mathematics, 22.06.2019 06:00

Kelly walks 0.7 mile to school. mary walks 0.49 mile to school. write an inequality using < ,> , or = to compare the distances they walk to school.

Answers: 1

Answer

You know the right answer?

Researchers collected a simple random sample of the times that 81 college students required to earn...