MS 1023: Business Statistics with Computer Applications I
Summer 2013 Test 1 Name: Student ID: Solutions
1 2 3 4 5 Total
20 20 20 20 20 100
1.
For a sample of 30 drivers filling gas at a gas station, the following data were collected for the amount that they paid at the pumps. 30.87 31.24 31.93 32.11 32.94 33.33 35.04 35.68 39.03 39.59 40.16 40.41 41.67 42.55 42.61 43.21 44.16 44.73 45.36 47.11 47.98 48.86 51.21 51.67 55.08 55.64 57.19 57.36 58.42 58.83
(a) Using the intervals in the following table, find the frequency, class midpoint, cumulative frequency, relative frequency and cumulative relative frequency for each class. (10) Class Midpoint 32.5 37.5 42.5 47.5 52.5 57.3 Cumulative Frequency 6 10 18 22 24 30 Relative Frequency 0.2000 0.1333 0.2667 0.1333 0.0667 0.2000 1.00 Cumulative Relative Frequency 0.2000 0.3333 0.6000 0.7333 0.8000 1.0000
Interval 30 – up to 35 35 – up to 40 40 – up to 45 45 – up to 50 50 – up to 55 55 – up to 60 Total
Frequency 6 4 8 4 2 6 30
(b) Use the frequencies that you found in part (a) to construct a histogram for this distribution. (5) Frequency 10 8 6 4 2
30
35
40
45
50 Expenses 1
55
60
65
70
(c) Use the frequencies that you found in part (a) to construct a frequency polygon for this distribution. (5)
Frequency
10 8 6 4 2
30
35
40
45
50
55
60
65
70
Expenses
2. A sample of n 15 male customers was selected. The times taken for a haircut in minutes in a barber shop for these customers are given in the following. Show your work and use appropriate notation for each question. 15 12 23 12 24 20 21 9 18 17 14 8 15 17 15
(a) Find the median, mode and mean of the times in the sample. You may use the table in part (d). (5) The sorted data is 8 9 12 12 14 15 15 15 17 17 18 20 Mode 21 15 23 24
n 1 15 1 8 The median is the 8th observation, Median 15 2 2 xi 240 16 . x Mean n 15
(b) Find the first and third quartiles of...