Last year, the standard deviation of the ages of the students at UA was 1.8 years. Recently, a sample of 31 students had a standard deviation of 2.1 years. We are interested in testing to see if there has been a significant change in the standard deviation of the ages of the students at UA. The null hypothesis is  a. µ > 1.8 b. µ = 1.8 c. σ > 1.8 d. σ = 1.8 The test statistic (

A sample of n=36 scores has a standard error of 3. What is the standard deviation of the population from which the sample is obtained?

A particular fruit's weights are normally distributed, with a mean of 271 grams and a standard deviation of 28 grams.If you pick 3 fruits at random, then 7% of the time, their mean weight will be greater than how many grams?Give your answer to the nearest gram.

A particular fruit's weights are normally distributed, with a mean of 689 grams and a standard deviation of 13 grams.If you pick 10 fruits at random, then 4% of the time, their mean weight will be greater than how many grams?Give your answer to the nearest gram.

Last year, the standard deviation of the ages at UTM was 1.8 years. Recently, a sample of 61 students had a standard deviation of 2.1 years. We are interested in testing to see if there has been a significant increase in the standard deviation of the ages of the students at UTM. Assume ages are Normally distributed. The p-value for this test is

A population is known to be normally distributed with standard deviation known to be 8.5.  In order to test the hypothesis that the true value of the mean is 17 researchers collect a sample of size 33 and calculate the sample mean to be 14.  State the distribution of the sample mean and then test this hypothesis using the appropriate test.

suppose that for a sexually active male drosophila fruit fly in a particular genetics lab the population mean lifespan is 38.9 days with a population standard deviation of 12.0 days when she experimentally removed all females from a simple random sample of 24 this drosophila flies in her lab a researcher in the slab found that 24 sexually inactive males had a mean lifespan of 62.5 days with a standard deviation of 14.1 days answer the questions below about the experiment and about testing weather sexual activity affects how long males Drosophila live. How do you find the Critical Value? How do you find theP-Value? reject or fail to reject the null hypothesis?