For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding.

What percentage of your campus student body is female? Let p be the proportion of women students on your campus.

(a) If no preliminary study is made to estimate p, how large a sample is needed to be 99% sure that a point estimate p̂ will be within a distance of 0.03 from p? (Round your answer up to the nearest whole number.)
___students.

(b) A report indicates that approximately 60% of college students are females. Answer part (a) using this estimate for p. (Round your answer up to the nearest whole number.)
___students.

An article in the San Jose Mercury News stated that students in the California state university system take 5 years, on average, to finish their undergraduate degrees. A freshman student believes that the mean time is less and conducts a survey of 38 students. The student obtains a sample mean of 6.1 with a sample standard deviation of 1.5. Is there sufficient evidence to support the student's claim at an α=0.01α=0.01 significance level?

Determine the null and alternative hypotheses. Enter correct symbol and value.

1) H0: μ= ?????

2) Ha: μ < ?????

3) Determine the test statistic. Round to four decimal places.
t= ??????

4) Find the p-value. Round to 4 decimals.
p-value = ???????

For some colleges, there are more applicants than there are openings. This requires colleges to implement a method for selecting students that utilizes criteria believed to predict how well a given student will perform in their college. For example, colleges will use a multiple regression equation that uses high school GPA, test score from the ACT or SAT (college entrance exams), and high school academic ranking (i.e., the quality of the high school) to predict how well a prospective student will do in their college. Describe at least 3 factors/variables you think colleges should use in selecting prospective students into their school. Your initial post must contain at least 10 sentences.

Can you break it down how I should do it?

Scores on a university exam are Normally distributed with a mean of 70 and a standard deviation of 10. The professor teaching the class declares that a student will receive a “F” if his or her score is below 50.

1. Using the 68-95-99.7 rule, what percent of students will receive “F”?

2. Using the 68-95-99.7 rule, what percent of students will score between 60 and 90?

3. Using the standard Normal distribution tables, the area under the standard Normal curve corresponding to –1.0 < Z < 1.0 is:

a. 0.3085.

* b. 0.6828.

c. 0.5328.

d. 0.2815.

A collage register has received numerous complains about the online registration procedure at her collage, alleging that the system is slow, confusing, and error prone. She wants to estimate the proportion of all students at this collage who are dissatisfied with the online registration procedure.

1. What is the most conservative estimates of the sample size that would limit the maximum error to be within 0.05 of the population proportion for a 90% confidence interval
2. Assume that a preliminary study has shown that 70% of the students surveyed at this collage are dissatisfied with the current online registration system. How large a sample should be taken in this case so that the maximum error to be within 0.05 of the population proportion for a 95% confidence interval?

Exercise 12. A researcher claims that the proportion of students that are pursuing a Bachelor of Arts degree and must work full time matches the distribution shown in the table on the left below. To test this claim, the researcher randomly surveyed 200 students, 50 from each year of study). The results are shown table on the right. At α = 0.05, is there evidence to support the researcher’s claim that the findings match the claimed distribution?

Researcher's Claim

CLASS Work full-time

Freshman 30%

Sophomore 32%

Junior 34%

Senior 38%

Researcher’s findings (n = 50 per class)

CLASS Work full-time

Freshman 14

Sophomore 18

Junior 17

Senior 21

Whether we are conducting a hypothesis test with regards to a one population parameter or two population parameters (usually the difference between two population parameters), the concept of p-value is extremely important in making a decision with respect to the null hypothesis. A very common mistake in elementary statistics is interpreting the p-value of a hypothesis test. Many students think that the p-value is the probability that the null hypothesis is true or that it is the probability of rejecting the null hypothesis:

• Explain why you think many students erroneously come to these conclusions.
• In your own words, explain what the p-value represents.
• What pages of the reading in OLI support your explanation? (ignore this question)

The national average on a reading test is 72. The average for a sample of 80 students in a certain geographical region who took the exam is 70. If the population standard deviation is 12, then test the claim that the average test score for students in this region statistically different from the national average. Let LaTeX: \alphaα =5% .

State the claim: LaTeX: H_0\:\:\:\muH 0 μ ______ 72

LaTeX: H_1\:\muH 1 μ LaTeX: \ne≠72 claim

Determine the direction of the tails: Left, Right, or Two:

Find the critical value: +/-

Compute Test Point (round to 2 place values) :

Do we Reject or Do Not Reject?

Summarize: There is enough evidence to _______________ the claim.

Scores on the SAT critical reading test in 2015 follow a Normal distribution with a mean of 495 and a standard deviation of 116

a. What proportion of students who took the SAT critical reading test had scores above 600?

b. What proportion of students who took the SAT critical reading test had scores between 400 and 600?

c. Jacob took the SAT critical reading test in 2015 and scored a 640. Janet took the ACT critical reading test which also follows a Normal distribution with a mean of 21 and a standard deviation of 5.5. Janet scored a 31 on the ACT critical reading test. Who did better?