Statistical Inferences — Unit test Answers

A scientist calculated the mean and standard deviation of a data set to be and . She then found that she was missing one data value from the set. She knows that the missing data value was exactly 3 standard deviations away from the mean. What was the missing data value?

Johnni guessed on all 8 questions of a multiple-choice quiz. Each question has 4 answer choices. What is the probability that she got exactly 3 questions correct? Round the answer to the nearest thousandth.

Kavita has been assigned the task of studying the average customer receipt for a branch of a major restaurant chain. The average receipt for the chain is $72.00 with a standard deviation of $11.00. The branch she is studying has an average bill of $67.00 for the last 40 receipts. She needs to know if this falls below the chain’s average. She will use a 1% level for significance because she does not want to inadvertently report the restaurants income as below average.Upper-Tail Valuesa5%2.5%1%Critical z-values1.651.962.58Which choice depicts the result for Kavita’s hypothesis test?

A researcher wants to survey people from different age groups to analyze voting patterns. Which type of survey will best accomplish this goal?