For each of the following sampling scenarios, choose an appropriate test statistic for our hypothesis test on the population mean. Then calculate that statistic. Round your answers to two decimal places. (a) The sample has size 16, and it is from a normally distributed population with a known standard deviation of 3.5. O It is unclear which test statistic to use. (b) The sample has size 13, and it is from a normally distributed population with an unknown standard deviation. It is unclear which test statistic to use.

Suppose that we want to estimate the mean reading speed of second graders. The random sample of students' reading speeds we choose has a mean of 29.8 words per minute and a standard deviation of 2.7 words per minute. For each of the following sampling scenarios, determine which test statistic is appropriate to use when making inference statements about the population mean. (In the table, Z refers to a variable having a standard normal distribution, and t refers to a variable having a t distribution.)   Sampling Scenario Z t could use either Z or t unclear (1) The sample has size 95, and it is from a non-normally distributed population with a known standard deviation of 3.2.                 (2) The sample has size 19, and it is from a population with a distribution about which we know very little.

Use the following information for questions 3 and 4.  A study of class lengths at two schools was done using independent samples. 31 classes were chosen from each. The first school had a mean length of 50.1 minutes and a standard deviation of 1.6 minutes. The second school had a mean length of 48.9 and a standard deviation of 2.2 minutes. We want to determine at α = 0.01 if the means are different. Assume all test conditions are satisfied. What are the null and alternate hypotheses (write in equation/inequality form)?

You would like to construct a 95% confidence interval to estimate the population mean score on a nationwide examination in psychology, and for this purpose we choose a random sample of exam scores. The sample we choose has a mean of 511 and a standard deviation of 71. (a) What is the best point estimate, based on the sample, to use for the population mean? X ? (b) For each of the following sampling scenarios, determine which distribution should be used to calculate the critical value for the 95% confidence interval for the population mean. (In the table, Z refers to a standard normal distribution, and t refers to a t distribution.)

Use the information below to answer Questions #27 - 29. In a random sample of 6 mobile devices, the mean repair cost was $90.00 and the standard deviation was $14.00. Assume the population is normally distributed. Construct a 99% confidence interval for the population mean µ. Find the left end point for the confidence interval for the population mean. Round to the nearest hundreth as needed.

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Smith and Smith are Certified Public Accountants who are in love with statistical analysis for audit sampling because of its objectivity and precision.  They made an estimation of expected population deviation of their client’s accounts receivable to be 2.1% . However, they seem to have a rough idea that the sample is representative of the population and that its deviation approximates that of the population deviation.   They decided to set their sample deviation parameters at + 3 or – 3% Required: a. What will be the sample risk deviation tolerable at the lowest limit level for your audit? The total Accounts Receivable is $500,000.00. This is the assertion by management. b. What will be the sample risk deviation that is tolerable at the highest level?

We want to conduct a hypothesis test of the claim that for middle-aged adults the population mean of their cholesterol levels is less than 191.7 mg dL mg dL mg a random sample of such levels. The sample has a mean of 190.7 dL -0 O It is unclear which test statistic to use. For each of the following sampling scenarios, choose an appropriate test statistic for our hypothesis test on the population mean. Then calculate that statistic. Round your answers to two decimal places. (a) The sample has size 110, and it is from a non-normally distributed population with a known standard deviation of 19.1. Oz = 0t= (b) The sample has size 14, and it is from a population with a distribution about which we know very little. 2-0 Oz= 01-0 O It is unclear which test statistic to use. and a standard deviation of 18 Explanation Check . We choos X Ⓒ2022 McGraw Hill LLC. All Rights Reserved. Terms of Use | Privacy Cer