I took a sample of 20 students at St. Kate’s and measured their heights. I computed...

I took a sample of 20 students at St. Kate’s and measured their heights. I computed the sample mean (x bar) and want to construct a confidence interval. I want to create an approximate 95% confidence interval. What is this?

I took a sample of 20 students and recorded their height. X bar (sample mean) was 63 inches. The population standard deviation for height is 4 inches. What is the approximate 95% confidence interval?

A 99% confidence interval will always be wider than a 95% confidence interval. True or false?

When will x bar (sample mean) be distributed approximately normally?

I take a 30 person sample of heights from St. Kate’s students and calculated x bar. I want to construct a 90% confidence interval. What z value should I use?

Solutions

Expert Solution

orchestra answered 1 year ago

Next > < Previous

Related Solutions

Below are a set of heights (in inches) and GPA scores for a sample of 6 students.

Below are a set of heights (in inches) and GPA scores for a sample of 6 students.Height, GPA60, 4.055, 3.262, 3.758, 3.949, 2.461, 2.8 a) Find the correlation coefficient (r) for these two variables by hand b) Find the mean and standard deviation for each variable. c) Find the equation of the regression line to predict GPA from height by hand d) Based on this data, what is the GPA prediction for a student who is 56 inches tall?...

You took independent random samples of 20 students at City College and 25 students at SF...

You took independent random samples of 20 students at City College and 25 students at SF State. You asked each student how many sodas they drank over the course of a year. The sample mean at City College was 80 and the sample standard deviation was 10. At State the sample mean was 90 and the sample standard deviation was 15. Use a subscript of c for City College and a subscript of s for State. Calculate a point estimate...

1. Rangers took a random sample of live aspen trees and measured the base circumference of...

1. Rangers took a random sample of live aspen trees and measured the base circumference of each tree. The sample had 50 trees with a mean circumference of 15.57 inches. a. Find a 95% confidence interval for the population mean base circumference of all aspen trees in Roosevelt National Forest. Assume that the population standard deviation is 4.78 inches. You must show work for full credit. b. Would the 90% confidence interval for the population mean base circumference of aspen...

6. Last year it was found that on average it took students 20 minutes to fill...

6. Last year it was found that on average it took students 20 minutes to fill out the forms required for graduation. This year the department has changed the form and asked graduating student to report how much time it took them to complete the forms. Of the students 22 replied with their time, the average time that they reported was 18.5 minutes, and the sample standard deviation was 5.2. Can we conclude that the new forms take less time...

A sample of 31 people took a written driver’s license exam. Two variables were measured on...

A sample of 31 people took a written driver’s license exam. Two variables were measured on them: The result of the exam (0 = fail, 1 = pass), and how much time (in hours) the person studied for the exam. Using the data, fit an appropriate regression model to determine whether time spent studying is a useful predictor of the chance of passing the exam. Formally assess the overall fit of the model. Formally assess whether time spent studying is...

AT coaching: A sample of 10 students took a class designed to improve their SAT math...

AT coaching: A sample of 10 students took a class designed to improve their SAT math scores. Following are their scores before and after the class. Before After 451 454 453 463 491 511 526 529 473 493 440 466 481 482 459 455 399 404 383 420 Send data to Excel Part: 0 / 2 0 of 2 Parts Complete Part 1 of 2 (a) Construct a 95% confidence interval for the mean increase in scores after the class....

28 randomly selected students took the calculus final. If the sample mean was 87 and the...

28 randomly selected students took the calculus final. If the sample mean was 87 and the standard deviation was 11.7. construct a 92% confidence interval for the mean score students.

A researcher took a sample of 14 students and put them into three different groups. The...

A researcher took a sample of 14 students and put them into three different groups. The three different groups are taught the same materials but using a different teaching style. The styles are either in class, hybrid, or online. The students are graded between 0 and 20 for the final grades. The individual grades by groups is shown below. The group standard deviation is also shown below. You are hired to test if teaching style has an impact on the...

Thirty randomly selected students took the calculus final. If the sample mean was 75 and the...

Thirty randomly selected students took the calculus final. If the sample mean was 75 and the standard deviation was 7.2, construct a 99% confidence interval for the mean score of all students.

Assume that I asked heights of 40 female students. It turns out that average height and...

Assume that I asked heights of 40 female students. It turns out that average height and standard deviation of ladies in our class is 164 cm and 9 cm, respectively. For all computations, assume that the heights follow a normal distribution. For hypothesis test questions please use 5 step procedure. a. (CI) Find a 95% confidence interval for the height of the female students. b. (CI) Without making any computation, can you test whether ?=163 or not at ?=0.05? Why?...

Subjects