The mean number of minutes for app engagement by a table user is 7.5 minutes. Suppose...

The mean number of minutes for app engagement by a table user is 7.5 minutes. Suppose the standard deviation is 1.25 minutes. Take a sample of 80.

a. What are the mean and standard deviation for the sample mean number of app engagement by a tablet user?

b. Find the 90th percentile for the sample mean time for app engagement for a tablet user. Interpret this value in a complete sentence.

c. Find the probability that the sample mean is between 7 and 7.75 minutes.

d. What are the mean and standard deviation for the sums?

e. Find the 90th percentile for the sum of the sample. Interpret this value in a complete sentence.

f. Find the probability that the sum of the sample is at least 10 hours.

Solutions

Expert Solution

milcah answered 9 months ago

Next > < Previous

Related Solutions

Modify the Tip Calculator app to allow the user to enter the number of people in...

Modify the Tip Calculator app to allow the user to enter the number of people in the party. Calculate and display the amount owed by each person if the bill were to be split evenly among the party members. Code: ----------------TipCalculator.java----------------------- import javafx.application.Application; import javafx.fxml.FXMLLoader; import javafx.scene.Parent; import javafx.scene.Scene; import javafx.stage.Stage; public class TipCalculator extends Application { @Override public void start(Stage stage) throws Exception { Parent root = FXMLLoader.load(getClass().getResource("TipCalculator.fxml")); Scene scene = new Scene(root); // attach scene graph to scene...

Consider the following table of values, where t is the number of minutes and Q (...

Consider the following table of values, where t is the number of minutes and Q ( t ) is the amount of substance remaining in grams after t minutes. t 0 1 2 3 4 5 6 7 8 9 10 11 12 Q ( t ) 300 267 238 212 189 168 150 134 119 106 94 84 75 a. What is the initial value of Q ( t ) ? b. What is the half-life? c. Construct an...

Suppose that it is known that the number of minutes that the daily 1 pm train...

Suppose that it is known that the number of minutes that the daily 1 pm train from NJ Station arrives late to destination Linden is a random variable X with density function f(x) = {c/15^2(15^2-x^2), -15<x<15; 0, elsewhere. (a) Determine the value of c so that f(x) is a valid probability density function. (b) Explain why c must be a particular value. That is, explain why probability density functions must have the specific property that you used to solve part...

The National Survey of Student Engagement reported that the mean number of hours spent studying per...

The National Survey of Student Engagement reported that the mean number of hours spent studying per week for nursing majors is 18. Suppose a medical researcher obtained a random sample of 100 nursing majors, which yielded a sample mean study time of 19 19 hours. Assume the population standard deviation σ=10 hours. Test, using level of significance ?=0.05, whether the population mean study time for nursing majors is greater than 18 hours per week. ?crit= Find the test statistic ?data....

Suppose the mean delay at a station for a subway train is 7 minutes, with a...

Suppose the mean delay at a station for a subway train is 7 minutes, with a standard deviation of 1 minutes. A subway improvement lobbyist measures the delay of 64 randomly selected trains, and computes the mean delay. What distribution, including parameters, does this sample mean come from and why? Written work: Answer the question. In the box below: Enter the second parameter (in the usual order) of the distribution.

A researcher is interested in finding a 95% confidence interval for the mean number minutes students...

A researcher is interested in finding a 95% confidence interval for the mean number minutes students are concentrating on their professor during a one hour statistics lecture. The study included 41 students who averaged 34.7 minutes concentrating on their professor during the hour lecture. The standard deviation was 12.1 minutes. Round answers to 3 decimal places where possible. a. To compute the confidence interval use a distribution. b. With 95% confidence the population mean minutes of concentration is between and...

An educational organization in California is interested in estimating the mean number of minutes per day...

An educational organization in California is interested in estimating the mean number of minutes per day that children between the age of 6 and 18 spend watching television per day. A previous study showed that the population standard deviation was 21.5 minutes. The organization selected a random sample of n = 251 children and recorded the number of minutes of TV that each person watched on a particular day. The mean time was 171.3 minutes. If the leaders of the...

A researcher is interested in finding a 90% confidence interval for the mean number minutes students...

A researcher is interested in finding a 90% confidence interval for the mean number minutes students are concentrating on their professor during a one hour statistics lecture. The study included 128 students who averaged 42.3 minutes concentrating on their professor during the hour lecture. The standard deviation was 10.7 minutes. Round answers to 3 decimal places where possible. a. To compute the confidence interval use a _____ (t? or z?) distribution. b. With 90% confidence the population mean minutes of...

A researcher is interested in finding a 95% confidence interval for the mean number minutes students...

A researcher is interested in finding a 95% confidence interval for the mean number minutes students are concentrating on their professor during a one hour statistics lecture. The study included 133 students who averaged 41.3 minutes concentrating on their professor during the hour lecture. The standard deviation was 13.3 minutes. Round answers to 3 decimal places where possible. a. To compute the confidence interval use a ? t z distribution. b. With 95% confidence the population mean minutes of concentration is...

A researcher is interested in finding a 99% confidence interval for the mean number minutes students...

A researcher is interested in finding a 99% confidence interval for the mean number minutes students are concentrating on their professor during a one hour statistics lecture. The study included 105 students who averaged 38.1 minutes concentrating on their professor during the hour lecture. The standard deviation was 11.2 minutes. Round answers to 3 decimal places where possible. a. To compute the confidence interval use a ? z t distribution. b. With 99% confidence the population mean minutes of concentration is...

Subjects