# PracticeS8

3997 words 16 pages
A) mean, median, SD, correlation, histograms

1) Find the mean, median, SD, IQR for the following data set:
5 5 8 10 12 15 15 19 20 21

What are the values of the SD & IQR ?

2) Find the mean, median, SD & IQR for the data in (1) after it has been transformed as follows: new value = 2.8(old value) – 7.2 Which statement is true ?

a) all four measures change so that new value = 2.8(old value) – 7.2
b) the mean, median & IQR change so that new value = 2.8(old value) – 7.2, but new SD = 2.8(old SD).
c) the mean & median change so that new value = 2.8(old value) – 7.2, but the SD & IQR change so that new value = 2.8(old value)

3) Find the height of the density

a) .50 b) .18 c) .32 d) .68 e) none of these

(3) Find the area between 15 & 20 under a normal curve centered at 20, if the area above 25 is .14

a) .20 b) .24 c) .26 d) .36 e) .40

(4) The daily number of hits received by statistics.com is approximately normally distributed with mean = 1224 & SD = 154. What percentage of days does this website receive more than 1000 hits?

a) .855 b) .882 c) .900 d) .926 e) .957

(5) In (4), on the busiest 10% of days, statistics.com receives about __?__ hits or more.

a) 1421 b) 1480 c) 1500 d) 1526 e) 1554

(6) The daily numbers of visitors to the Tate Modern Gallery is approximately normally distributed with mean = 3840 & SD = 200. What percentage of days do more than 3955 people visit the Tate ?

a) .15 b) .18 c) .21 d) .24 e) .28 (7) In (6), on the busiest 3% of days, at least _?_ people visit the Tate.

a) 4158 b) 4188 c) 4216 d) 4260 e) 4355

(8) Management claims that the number of fans attending a Triple Cities Tigers home game is approximately normally distributed with mean = 1850 & SD = 100. Assuming this is true, what percentage of games next year will be attended by more than 2000 fans ?

a) 2.28 b) 6.68% c) 8.92% d) 10.12% e) 12.44%