Reference no: EM132358040

1. A random sample of math majors taking an introductory statistics course were surveyed after completing the final exam. They were asked, "How many times did you review your final exam before handing it in to the professor?" The results are displayed in a probability density function for the random variable X, the number of times students reviewed their exam before handing it in. Find the standard deviation of X.

• Round the final answer to two decimal places.  

X            P(X = x)                      

1             1/5              

2             2/5

7             2/5

1. A softball pitcher has a 0.626 probability of throwing a strike for each curve ball pitch. If the softball pitcher throws 30 curve balls, what is the probability that no more than 16 of them are strikes? Round your answer to 3 decimal places.
2. Alice was told that her reading test score was 1 standard deviation below the mean. If test scores were approximately normal with μ=86 and σ=4, what was Alice's score? Do not include units in your answer. For example, if you found that the score was 86 points, you would enter 86.