A researcher compares the effectiveness of two different instructional methods for teaching anatomy. A sample of 215215 students using Method 1 produces a testing average of 55.555.5. A sample of 242242 students using Method 2 produces a testing average of 64.264.2. Assume that the population standard deviation for Method 1 is 7.957.95, while the population standard deviation for Method 2 is 18.2118.21. Determine the 90%90% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2.
Step 1 of 3 :
Find the point estimate for the true difference between the population means.
In: Statistics and Probability
Professor Jennings claims that only 35% of the students at Flora College work while attending school. Dean Renata thinks that the professor has underestimated the number of students with part-time or full-time jobs. A random sample of 85 students shows that 38 have jobs. Do the data indicate that more than 35% of the students have jobs? Use a 5% level of significance.
What is the level of significance?
State the null and alternate hypotheses.
What is the value of the sample test statistic? (Round your answer to two decimal places.)
Find the P-value. (Round your answer to four decimal places.)
In: Statistics and Probability
Researchers wanted to test whether viewing a scary movie before going to bed affects the number of hours people sleep. 40 students were asked to participate. Each of these students was asked to watch a scary movie within an hour of going to bed, and the number of hours they slept was recorded. The mean number of hours slept for these students was 5.5 hours. In general, students sleep an average of 7 hours per night with a standard deviation of 1 hour. Use the hypothesis testing procedure to determine if there is a difference between individuals who watch a scary movie before bed and those who do not on number of hours slept (α = .05)
In: Statistics and Probability
the university would like to conduct a study to estimate the true proportion of all university students who have student loans. According to the study, in a random sample of 215 university students, 86 have student loans.
(a) Construct a 95% confidence interval for estimating the true proportion of all university students who have student loans
(b) Provide an interpretation of the confidence interval in part (a).
(c) Conduct an appropriate hypothesis test, at the 5% level of significance to test the claim that more than 30% of all university students have student loans.
In: Statistics and Probability
A survey consisting of a sample of 463 first-year college students at a certain university asked, “About how many hours do you study during a typical week?” The mean response from the sample of students was 15.3 hours. Suppose we know that study times follow a Normal distribution with a standard deviation of 8.5 hours for all first-year students. Construct a 99% confidence interval for the mean study time of all first-year college students.
a. 14.28 ≤ � ≤ 16.32
b. 14.65 ≤ � ≤ 15.95
c. 14.53 ≤ � ≤ 16.07
d. −6.59 ≤ � ≤ 37.19
Solve the problem and show all your work below:
In: Statistics and Probability
1. Compute the probability of no successes in a random sample of three items obtained from a population of 12 items that contains two successes. What are the expected number and standard deviation of the number of successes from the sample?
a) what is the expected number of the sample?
b) what is the standard deviation of the number of successes from the sample?
2. A professor of management has heard that 8 students in his class of 40 have landed an internship for the summer. Suppose he runs into three of his students in the corridor.
a) find the probability that none of these students has landed an internship.
b) find the probability that at least one of these students has landed an internship.
In: Statistics and Probability
The university would like to conduct a study to estimate the true proportion of all university students who have student loans. According to the study, in a random sample of 217 university students, 88 have student loans.
(a) Construct a 99% confidence interval for estimating the true proportion of all university students who have student loans
(b) Provide an interpretation of the confidence interval in part (a).
(c) Conduct an appropriate hypothesis test, at the 1% level of significance to test the claim that more than 30% of all university students have student loans.
Provide the hypothesis statement
Calculate the test statistic value
Determine the probability value
In: Statistics and Probability
In: Statistics and Probability
It is estimated that 13% of those taking the quantitative methods portion of the certified public accountant (CPA) examination fail that section. Seventy seven students are taking the examination this Saturday. a-1. How many would you expect to fail? (Round the final answer to 2 decimal places.) Number of students a-2. What is the standard deviation? (Round the final answer to 2 decimal places.) Standard deviation b. What is the probability that exactly six students will fail? (Round the final answer to 4 decimal places.) Probability c. What is the probability at least six students will fail? (Round the final answer to 4 decimal places.) Probability
In: Statistics and Probability
On January 30th, 2018, Dr. Ziegler took a random sample of STAT 104 students.1 Students were asked how many Facebook friends they had. Out of 30 respondents who had Facebook accounts, the mean number of friends was 589.10 with a standard error of 72.98.
Describe the parameter of interest in context.
What is the 95% confidence interval?
Interpret the 95% confidence interval.
Is 500 friends a plausible value for the population of all STAT 104 students on January 30th, 2018? Explain.
Is 750 friends a plausible value for the population of all STAT 104 students on January 30th, 2018? Explain.
In: Statistics and Probability