MATH534 Final Exam Solution’s Study Guide1. The following numbers represent the weights in pounds of six 7-year
old children in Mrs. Jones' second grade class (25, 60, 51, 47, 49, 45).
Find the mean, median, mode, variance, and standard deviation.
Solution: This would be a sample from the class
mean = 46.166 (=AVERAGE)
median = 48 (=MEDIAN)
mode does not exist (looking at the data)
variance = 134.5667 (=VARIANCE.S)
standard deviation =11.60029 (=STDEV.S)
These can also be found using the MATH533 spreadsheet.
2. If the variance is 846, what is the standard deviation?
Solution: standard deviation = square root of variance = sqrt(846) =
29.086
3. If we have the following data: 34, 38, 22, 21, 29, 37, 40, 41, 22, 20, 49,
47, 20, 31, 34, 66. Draw a stem and leaf. Discuss the shape of the
distribution.
Solution:
2 | 2 1 9 2 0 0
3 | 4 8 7 1 4
4 | 0 1 9 7
5 |
6 | 6
This distribution is right skewed (positively skewed) because the “tail”
extends to the right.
4. For two events, C and D, P(C) = 0.6, P(D)=0.3, and P(C|D) = 0.2. Find
P(CD).
Solution:
P(CD) = P(D) * P(C|D)
= 0.3*0.2
= 0.06