what raw score is needed to be in the bottom 16%? a group of students take a statistics exam where the average was m=90 and the standard deviation was SD = 7.8. answer with raw scores, z scores and what in particular you shaded when creating a curve and the final answer.

on a nationwide math test,the mean was 63 and the standard deviation was 7. if roberto scored 75,what was his z-score?

The first picture is the question and the second is the ones that I need help with. Thanks

Jerome made a grade of 89.7 on his test. The mean of the test scores was 71.4 with a standard deviation of 6.8. In what top percent can Jerome say he is, based on the tes

In a study 10 people were given a test. The mean test score was 78.9 points. The standard deviationfor the test scores was 5.2 points. If an 11th person takes the test and scores 77 points, predict what willhappen to the mean and standard deviation. Circle the appropriate conclusion in the sentences below. The mean will increase // decrease // stay the same.  The standard deviation will increase // decrease // stay the same.

Adrianna is trying to figure out the sample size for the data set she wants to collect. She thinks the population standard deviation could be as low as 120 or as high as 136. Explain to Adrianna the impact standard deviation will have on her sample size.