For a question on the AP Economics Exam, the time to completion is a normally distributed random variable with a mean of 16.20 seconds and a variance of 0.2704 seconds. Find the probabilities that the time to completion will be
a. at least 17 seconds; b. (4 pts) at most 16 seconds; and, c. (4 pts) anywhere from 16 to 17 seconds.
Here it is given that
a. Now we need to find
As distribution is normal we can convert x to z
b. Now we need to find
As distribution is normal we can convert x to z
c. Now we need to find
For a question on the AP Economics Exam, the time to completion is a normally distributed...
The time to complete the Advanced Placement (AP) Statistics Exam in previous years is normally distributed with an average time of 2.5 hours. Because of school closures due to COVID-19, the College Board offered an at- home test for the 2020 AP Statistics Exam. A teacher feels that students, on average, will have a different completion time for the at-home exam. They take a random sample of 25 students that took the exam and their mean time was 2.68 hours...
Question Completion Status: Your instructor (Katie) believes that the average time of taking this exam is equal to 140 minutes. A sample of 4 students was taken and the following exam times were obtained. Assume the distribution of the population is normally distributed. Sample: 150, 150, 180, 170 (Sample Std. Dev = 15) The critical value for this test at a 0.1 level of significance is: O a. 1.638, -1.638 1.645, -1.645 Ob. Olc. 2.353,-2.353 Od. 1.285, -1.285 QUESTION 17...
Suppose that the time duration of a minor surgery is approximately normally distributed with mean equal to 800 seconds and a standard deviation of 40 seconds. Find the probability that a random sample of 16 surgeries will have average time duration of less than 775 seconds. Use the central limit theorem 9-
Q1: The marks of final exam on a calculus exam are normally distributed with a sample standard deviation of 0.51. A random sample of 12 scores on the exam has a mean of 2.71. Find a 90% confidence interval for the mean of the exam grades. 20.05 = 1.64 and 10.05 = 1.80
Based on experience, the time required to complete a college statistics exam is normally distributed with a mean of 42 minutes and a standard deviation of 8 minutes. The class is a large lecture and has 900 students. Simulate the exam completion times for the 900 students. (Convert to a percent then round to two decimals) a) What percent of students are still working when the professor stops the exam at 50 minutes? % b) What percent of students are...
A random variable X is normally distributed with a mean of 121 and a variance of 121, and a random variable Y is normally distributed with a mean of 150 and a variance of 225. The random variables have a correlation coefficient equal to 0.5. Find the mean and variance of the random variable below. Av-218 (Type an integer or a decimal.) σ (Type an integer or a decimal.)
4. Scores on an exam are normally distributed with a population standard deviation of 5.5. A random sample of 50 scores on the exam has a mean of 28. (a) (5 pts.) Construct 80% confidence interval. (b) (5 pts.) Construct 85% confidence interval. (c) (5 pts.) Construct 92% confidence interval. (d) (5 pts.) When confidence level increases what will happen to the confidence interval.
The time required for a student to complete a Statistics exam is normally distributed with a mean of 55 minutes and a standard deviation of 12 minutes. What percent of students take between 40 and 50 minutes to complete an exam? At what point in time will 25 percent of the students have completed the exam?
On a certain statistics exam, the time for students to submit the exam is normally distributed with a mean of 0.9 hours and a standard deviation of 0.1 hours. What is the probability that a randomly selected student will take longer than an hour and a half to submit the exam? O 0.707 1 0.5 0.0000000001 Page 14 Previous Page Next Page
On a certain statistics exam, the time for students to submit the exam is normally distributed with a mean of 0.9 hours and a standard deviation of 0.1 hours. What is the probability that a randomly selected student will take longer than an hour and a half to submit the exam? O 0.707 O1 0.5 0.0000000001 Page 14 Previous Page Next Page