Reference no: EM132461951

1. SAT scores are normally distributed. Suppose the mean is 1000 and the standard deviation is 200.

(a) What percentage of students score higher than 1200?

(b) Harry scored 800 on the SAT. What is the percentage of students that scored less than or the same as Harry?

(c) Hermione scored better than about 97.5% of other students. What was her SAT score?

(d) If 400 students from a school district take the SAT in a given year, how many of them do you expect will have a score less than 1200?

2. An industrial manufacturing company produces jet skis with engines that have a mean horse power of 210. The power measurements are normally distributed with a standard deviation of 15. To determine whether to purchase a few of the jet skis, the owner of a marina plans to take a sample of 9 jet skis and measure the horsepower. What is the probability that the engines from the sample have a mean horsepower between 205 and 215?

3. A normal distribution has mean μ= 10 and standard deviation σ= 2.

(a) How many standard deviations away from the mean is x= 6?

(b) What percentage of data has values between 6 and 14? How do you know?

(c) What percentage of data has values less than or equal to 6? How do you know?

(d) What percentage of data has values less than or equal to 14? How do you know?

(Draw graphs to see how you got the answers)