A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1484 and the standard deviation was 312. The test scores of four students selected at random are 1890, 1240, 2210, and 1370. Find the z-scores that correspond to each value and determine whether any of the values are unusual.

With the extra data value,  the range, standard deviation, and variance is?

In a survey, 80% of the voters support a particular referendum.  If 30 voters are chosen, find the standard deviation of the number of voters who support the referendum.

On a multiple choice test with 10 questions, each question has four possible answers, one of which is correct. For students who guess at all answers, find the standard deviation for the number of correct answers.

On a multiple choice test with 20 questions, each question has four possible answers, one of which is correct. For students who guess at all answers, find the standard deviation for the number of correct answers. Round off the three decimal places.

In the School of Medicine at Florida State University, the mean IQ is 116 with a standard deviation of 14. Given this information, what IQ score would correspond to a z-score of -1.5?     123     118     104     95

You have a sample of 48 randomly selected Vancouverites. On average (the sample mean), the people in your sample spent 425 hours eating food in 2020. The least time a person in the sample spent eating food in 2020 is 367 hours and the most time a person in the sample spent eating food in 2020 is 484 hours. What would be your best guess about the population standard deviation of the time a Vancouverite spent eating food in 2020? Give the number and explain (including assumptions you make about the population distribution).

Mario's weekly poker winnings have a mean of $353 and a standard deviation of $67. Last week he won $185. How many standard deviations from the mean is that?

Find the indicated IQ score. The graph to the right depicts IQ scores of adults, and those scores are normally distributed with a mean of 100 and a standard deviation of 15. Click to view page 1 of the table. Click to view page 2 of the table. The indicated IQ score, x, is (Round to one decimal place as needed.)

A successful basketball player has a height of 6 feet 11 ​inches, or 211 cm. Based on statistics from a data​ set, his height converts to the z score of 5.17. How many standard deviations is his height above the​ mean?