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Suppose you are hired to determine the true average amount of money that college students make while working on-campus jobs. If you want to be 95% confident that you are within $80 of the actual value, how many students would you need to survey? Assume that the true standard deviation is $600.  Reminder: It’s impossible to survey a fraction of a college student.

Consider the following sample data set below. What is the standard deviation? {12, 2, 8, 12, 15, 24, 20, 6, 22, 6} Make sure to round your final answer to 2 decimal places. For example, if you thought the final answer was 87.6543 then you would type in 87.65

A recent study was conducted and it found that IQ’s are normally distributed with a mean of 100 and a standard deviation of 15. Use this information to find the following probability.  What is the probability that a randomly selected individual would have an IQ less than 80 or greater than 110?   Make sure to write your answer as a decimal rounded to 3 decimal places. For example, if you thought the answer was 23.173% then you would type in 0.232.

A professor at a local community college decided to try out a new lecture format for his statistics class, and he was curious how well students performed using this new format. So the professor decided to record every student’s final grade at the end of the semester to determine how effective this new lecture format was. There were 26 students in his class and their final letter grades are shown below.  Distribution Table of Letter Grades Letter Grade Count/Frequency A Left Blank on Purpose B 8 C 10 D 3 F 1 Total 26 What percentage (relative frequency) of students received an A? Give your answer as a percentage rounded to 2 decimal places (i.e. If the answer is 17.43%, simply type in 17.43)

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. Use this information to answer the following question. What is the probability that a randomly selected person will have an IQ score of at least 111? Make sure to type in your answer as a decimal rounded to 3 decimal places. For example, if you thought the answer was 0.54321 then you would type in 0.543.

A recent study was conducted and it found that IQ’s are normally distributed with a mean of 100 and a standard deviation of 15. Use this information to find the following probability.  What is the probability that a randomly selected individual would have an IQ between 87 and 109?   Make sure to write your answer as a decimal rounded to 3 decimal places. For example, if you thought the answer was 23.173% then you would type in 0.232.

A professor at a local community college decided to try out a new lecture format for his statistics class, and he was curious how well students performed using this new format. So the professor decided to record every student’s final grade at the end of the semester to determine how effective this new lecture format was. There were 26 students in his class and their final letter grades are shown below.  Distribution Table of Letter Grades Letter Grade Count/Frequency A 4 B 8 C 10 D 3 F Left Blank on Purpose Total 26 What percentage (relative frequency) of students received an F? Give your answer as a percentage rounded to 2 decimal places (i.e. If the answer is 17.43%, simply type in 17.43)

A recent study was conducted and it found that IQ’s are normally distributed with a mean of 100 and a standard deviation of 15. Use this information to find the following probability.  What is the probability that a randomly selected individual would have an IQ of at most 122?   Make sure to write your answer as a decimal rounded to 3 decimal places. For example, if you thought the answer was 23.173% then you would type in 0.232.

A recent study was conducted and it found that IQ’s are normally distributed with a mean of 100 and a standard deviation of 15. Use this information to find the following probability.  What is the probability that a randomly selected individual would have an IQ of at least 111?   Make sure to write your answer as a decimal rounded to 3 decimal places. For example, if you thought the answer was 23.173% then you would type in 0.232.

Consider the following sample data set below. Calculate the range.  {12, 2, 8, 12, 15, 24, 20, 6, 22, 6} Make sure to round your final answer to 2 decimal places. For example, if you thought the final answer was 87.6543 then you would type in 87.65