Use the student dataset for this question. students are considered “full-time” students if they are enrolled in 12 or more credits in a given semester. 

What percent of respondents in the student dataset are “full-time” students? Consider your result to part (a) as the best estimate for the probability of any randomly selected student being full-time. Based on that response, what is the probability that in a class of 20 students they will all be full-time?

 

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1. If you wanted to find the difference in Elementary Statistics grades between students who transferred to CSULB from a community college and students who entered CSULB straight out of high school, what test statistic would you use?

2. If you wanted to find the difference in grades among students who took Elementary statistics in their Freshman year, Sophomore year, Junior year, or Senior year in college, what test statistic would you use?

3. If you wanted to see if there is a difference among students who took Elementary statistics in their Freshman year, Sophomore year, Junior year, or Senior year in college, and whether their age at the time affects their grade, what test statistic would you use?

The Stanford-Binet Intelligence Scale is an intelligence test, which, like many other IQ tests, is standardized in order to have a normal distribution with a mean of 100 and a standard deviation of 15 points.

As an early intervention effort, a school psychologist wants to estimate the average score on the Stanford-Binet Intelligence Scale for all students with a specific type of learning disorder using a simple random sample of 36 students with the disorder.

Determine the margin of error, mm, of a 99% confidence interval for the mean IQ score of all students with the disorder. Assume that the standard deviation IQ score among the population of all students with the disorder is the same as the standard deviation of IQ score for the general population, σ=15σ=15 points.

Give your answer precise to at least two decimal places.

The Stanford-Binet Intelligence Scale is an intelligence test, which, like many other IQ tests, is standardized in order to have a normal distribution with a mean of 100 and a standard deviation of 15 points.

As an early intervention effort, a school psychologist wants to estimate the average score on the Stanford-Binet Intelligence Scale for all students with a specific type of learning disorder using a simple random sample of 36 students with the disorder.

Determine the margin of error, mm, of a 99% confidence interval for the mean IQ score of all students with the disorder. Assume that the standard deviation IQ score among the population of all students with the disorder is the same as the standard deviation of IQ score for the general population, σ=15σ=15 points.

Give your answer precise to at least two decimal places.

1)At a certain university, the average cost of books was $370 per student last semester and the population standard deviation was $75. This semester a sample of 55 students revealed an average cost of books of $400 per student. The Dean of Students believes that the costs are greater this semester. What is the test value for this hypothesis?

a)0.40

b)0.55

c)22.00

d)2.97

2)It has been claimed that at UCLA at least 40% of the students live on campus. In a random sample of 250 students, 90 were found to live on campus. Does the evidence support the claim at  = .01?

a)No because the test value is in the rejection region

b)Yes because the test value is not in the rejection region

c)Yes because the test value is in the rejection region

d)No because the test value is not in the rejection region

According to a study conducted by ABODO, about 70% of all college students use an online dating app. Suppose you want to know if Harvard students are similar to their national peers. You ask a random sample of 125 Harvard students and find that 78 of them use an online dating app.

a. Does this sample provide significant evidence at the ? = .05 level that the true proportion of Harvard students that use an online dating app is different than the ABODO estimate? Conduct a hypothesis test to justify your answer.

b. Give an interpretation in context for the p-value that you calculated in part a.

c. Your colleague constructed a confidence interval based on your sample and found that it didn’t include 0.7. Give an example of a confidence level they might have used. Justify your answer.

a statistics professor in an attempt to make students more aware of their study habits, began requiring students to maintain a daily activity log for the class. The log consisted simply of recording the hours and a brief summary of what was done for the class on a daily basis, such as reading the text, working on homework, copying notes. For the year previous when the log was not completed, the professor observed 22 of 137 students received an F in the course. For the year the activity logs were required, the professor observed 9 of 122 student received an F in the course.

a) Based on the data does it seem reasonable to assume the student logs are working to reduce the number of students who fail the course?

b) Briefly discuss the potential confounding factors and the validity of making the claim the the student logs is reducing failure in the course.

A study reported that 28 percent of middle school students in a certain state participate in community service activities. A teacher believes that the rate is greater than 28 percent for the middle school students in the teacher’s district. The teacher selected a random sample of middle school students from the district, and the percent of students in the sample who participated in community service activities was found to be 32 percent. Which of the following is the most appropriate method for investigating the teacher’s belief?

A two-sample z-test for a difference in population proportions A

A two-sample z-test for a difference in sample proportions B

A one-sample z-test for a sample proportion C

A one-sample z-test for a population proportion D

A one-sample z -test for a difference in population proportions E

Do cash incentives improve learning? A high-school teacher in a low-income urban school in Worcester, Massachusetts, used cash incentives to encourage student learning in his AP Statistics class. In 2010, 15 of the 80 students enrolled in his class scored a 5 on the AP Statistics exam. Worldwide, the proportion of students who scored a 5 in 2010 was 0.15. Is this evidence that the proportion of students who would score a 5 on the AP Statistics exam when taught by the teacher in Worcester using cash incentives is higher than the worldwide proportion of 0.15?

Conduct a hypothesis test at the significance level α = 0.05 to determine if evidence is present regarding the use of cash incentives to motivate AP Statistics students to do better on their AP exams.

The Stanford-Binet Intelligence Scale is an intelligence test, which, like many other IQ tests, is standardized in order to have a normal distribution with a mean of 100 and a standard deviation of 15 points.

As an early intervention effort, a school psychologist wants to estimate the average score on the Stanford-Binet Intelligence Scale for all students with a specific type of learning disorder using a simple random sample of 36 students with the disorder.

Determine the margin of error, ?m, of a 99% confidence interval for the mean IQ score of all students with the disorder. Assume that the standard deviation IQ score among the population of all students with the disorder is the same as the standard deviation of IQ score for the general population, ?=15 points.

Give your answer precise to at least two decimal places.

?= Points