Download Review Chapter 3

Review Chapter 3
Stats for Tech
Name: ___________________________
Date: ________________ Per: ________
MEASURES OF CENTRAL TENDENCY: (Note: The data for 1 – 3 are the same as 8 – 10.)
Find the mean, median, mode, and midrange. (round to the tenths)
1) Weights in pounds: 127, 145, 118, 162, 106, 143, 160, 215, 127, 132
(n=10)
Mean = __________ Median = __________ Mode = __________ Midrange = __________
2) Scores on IQ test: 118, 105, 115, 108, 106, 111, 99, 106, 111, 109, 98, 100, 121
(n=13)
Mean = __________ Median = __________ Mode = __________ Midrange = __________
3) Age: 41, 25, 19, 22, 67, 28, 32, 23, 55, 42, 24, 20, 57, 31, 21, 36, 63, 44, 29, 19
(n=20)
Mean = __________ Median = __________ Mode = __________ Midrange = __________
4) Complete the table. Find the mean, modal class, and mode of years teaching experience for
the sample of 80 college professors. (round to the tenths)
Class Limits
Frequencies (f) Midpoints (xm)
0–4
16
5–9
21
10 – 14
12
15 – 19
11
20 – 24
10
25 – 29
8
30 - 34
2
n = ________
Mean = _______________
f⋅xm
total = ________
Modal Class = _______________ Mode = ________________
MEASURES OF Variation: Complete the tables.
Then find the variance and standard deviation using the appropriate formulas.
5) The cost of ten speeding tickets randomly selected
x
30
65
70
40
55
60
35
50
95
70
x
x− x
(x − x )
2
total = __________
Show work with formula(s) here. (round to the tenths)
Range = ___________
Variance = ___________
Std Deviation = ___________
WEIGHTED MEANS: Use the formula for weighted means.
SHOW HOW YOU USED THE FORMULA
6) Find the mean of the hourly wages of 200 workers. One hundred workers make $6.00 per
hour, ten make $7.50 per hour, ten make $8.75 per hour, twenty make $5.80 per hour, and
sixty make $7.25 per hour. (round to the hundredths)
7) Tickets for a concert were priced in different amounts depending on the seating and how far in
advance the tickets were purchased. Find the mean cost of tickets if 400 tickets were sold for
$10 each, 300 tickets were sold for $15 each, 450 tickets were sold for $20 each, 200 tickets
were sold for $25 each, and 50 tickets were sold for $50 each. (round to the hundredths)
MEASURES OF POSITION: Find the range, upper quartile, lower quartile, interquartile
range, and any outliers. (Note: The data for 8 – 10 are the same as problems 1 – 3.)
8) Weights in pounds: 127, 145, 118, 162, 106, 143, 160, 215, 127, 132
* Range: __________
IQR:
__________
Upper Quartile: __________
(n=10)
Lower Quartile: __________
Outliers: __________
Show work!
9) Scores on IQ test: 118, 105, 115, 108, 106, 111, 99, 106, 111, 109, 98, 100, 121
* Range: __________
IQR:
__________
Upper Quartile: __________
(n=13)
Lower Quartile: __________
Outliers: __________
Show work!
10) Age: 41, 25, 19, 22, 67, 28, 32, 23, 55, 42, 24, 20, 57, 31, 21, 36, 63, 44, 29, 19
* Range: __________
IQR:
__________
Upper Quartile: __________
(n=20)
Lower Quartile: __________
Outliers: __________
Show work!
11) BOX-AND-WHISKER PLOT:
Construct a box-and-whisker plot for the IQ scores in problem #9.
94
96
98
100 102 104 106 108 110 112
114 116 118
120 122 124 126
COEFFICIENT OF VARIATION: (round to the tenths)
12) A random sample of pills made in Plant A was tested and found to have a mean of 47.3 mg of
medicine with a standard deviation of 2.1 mg. A sample of pills from Plant B was tested and
found to have a mean of 48.3 mg with a standard deviation of 8.2 mg.
Write a sentence comparing that variability of Plant A and Plant B.
13) A sample of the actual weights (in ounces) of the contents of cans of pet food have a mean of
7.81 ounces with a standard deviation of 0.40 ounces. A sample of the actual weights (in
pounds) of the contents of bags of dry pet food have a mean of 49.68 pounds with a standard
deviation of 1.74 pounds.
Write a sentence comparing that variability of canned pet food and bagged pet food.
14) Be able to label the following as:
(A) Measure of Central Tendency
(B) Measure of Variation
(C) Measure of Position
__________ Variance
__________ Percentiles
__________ Mean
__________ Range
__________ Mode
__________ Z Scores
__________ Standard Deviation
__________ Midrange
15) You should also be able to classify a graph as a
Symmetric Distribution, Positively Skewed Distribution, or Negatively Skewed Distribution.
Label the mean, median, and mode of each. (Draw the pictures – see 3.1 Notes).
Symmetric Distribution
Positively Skewed
Distribution
Negatively Skewed
Distribution