44 28 12 21 24 12 18 16 28 18
16 48 52 28 13 16 23 40 15 22
32 61 63 69 42 40 17 26 24 33
a.) Create a stem-and-leaf plot for the time-to-malfunction data.
b.) Which of the following descriptions are appropriate for the distribution of time to the first malfunction? Select all that apply.
i.) symmetric
ii.) unimodal
iii.) bimodal
iii.) skewed left
vi.) skewed right
iv.) uniform
1
2
3
4
5
6
2 2 3 5 6 6 6 7 8 8
1 2 3 4 4 6 8 8 8
2 3
0 0 2 4 8
2
1 3 9
Note: 1 | 2 means 12.
Note: don�t forget the note up above.
c.) What proportion of subjects had their first malfunction before twenty months?
10 /30 = 1/3
8. The following data is the amount of rainfall for our imaginary city on different days:
1.6, 1.9, 2.8, 3.5, 3.5, 3.7, 3.9, 4.3, 4.3, 4.4, 4.5, 4.7, 4.8, 4.9, 5.3, 5.9
The data is already arranged in increasing order and we�re going to make a box plot for it.
a.) first, find the mean, median, mode and range for the data.
Mean = 64/16 =4
Median = 4.3
Mode = 3.5, 4.3
Range = 5.9 � 1.6 = 4.3
b.) next, give Q1 and Q3, the IQR of the data, and the step number (which was the IQR multiplied by a number we talked about in class).
Q1 = 3.5
Q3 = 4.75
IQR = 1.25
Step # = 1.875
c.) now, prove or disprove if there exists any outliers in the data set.
3.5 � 1.875 = 1.625
and
4.75 + 1.875 = 6.625
Therefore, 1.6 is an outlier because it is less than 1.625.
d.) In the space provided, draw your box-plot with all the necessary information: draw points for outliers, draw the dashed region for the step number, etc�.
_____________________
o |----------------------------------|____________|________|--------------------------------|
1.6 2 2.5 3 3.5 4 4.5 5 5.5 5.9
End of test one � have a nice weekend!