Math 112 Elementary Statistics Name( print) _______________________________
Quiz 1 Spring 2009, February 4th Total points 36 Good Luck!
Directions:
 Use pencil.
 Use a ruler, if you don’t have one use ID card.
 Write neatly and to the point.
 Must show all logical work, step by step for full credit!
I. Define each word: (1 points each)
1. Parameter:____See book ____________________________________
2. Statistic: _____See book _______________________________________
3. Sample:______See book __________________________________________
4. Population:________See book_____________________________________
5. Simple Random Sample: __________See book___________________________
II. Give two specific example of each: ( 1 point each, 6 points total)
1. Quantitative discrete data: ( answers will differ)
i. ______ number of animals on a farm___
ii. _____number of soda cans in a box_______
2. Qualitative or categorical data:
i. _____Colors _____
ii. _____Social security number_
3. Quantitative continuous data:
i. ______My weight__
i. ______My age_
II. Given the data from the table below construct the following and interpret.
Math 112 class( spring ’07) Students age data
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21
21
22
23
23
24
24
24
24
24
24
24
25
26
26
26
26
27
27
29
30
32
32
32
33
34
40
47
48
49
1. Fill in the table below using Student’s Age data from above: ( 1 point each column)
Class
Boundary
Midpo
int
Frequency
Relative Frequency
( rounded to 2 decimal
places)
Cumulative Relative
Frequency (%)
21-25
20.5
23
15
42.86%
42.86%
26-30
25.5
28
10
28.57%
71.43%
31-35
30.5
33
6
17.14%
88.57%
36-40
35.5
38
1
2.86%
91.43%
41-45
40.5
43
0
0
91.43%
46-50
45.5 and 50.5
48
3
6.57%
~100 %
Sum
35
2. Construct a neat Relative Frequency Histogram (on the vertical axis %) labeling horizontal and
vertical axes, using the table above. ( 3 points)
I did this in class!!
Interpret (1 points each) :
3. ( skewed left or right or symmetric) ___Skewed right___________________
4. Majority of ages are between what class? Between 21-25 or if you think of majority as more then half
then majority is between 21-30
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IV.
Given the data from the table above (Age), identify and interpret the 5-number summary. ( 1
point each)
1. __Minimum Age is 21___
2. _Q1=25%, Q1=24, This means 25% of ages are less then 24 or 75% of ages are greater then 24._
3. _Q2=50%, Q3=26, This means 50% of ages are less then 26 or 50% of ages are greater then 26.
4. _Q3=75%, Q3=32, This means 75% of ages are less then 32 or 25% of ages are greater then 32.
5. __Maximum age is 49_
V. Find the z-score (round to two decimal places). Human body temperature has a mean of 98.2 F and a
standard deviation of 0.62F. Convert the given temperatures to z-scores. ( 4 points total)
i. 98.7F
ii. 99.8F
i. z 
98.7  98.2
 0.81
0.62
ii. z 
99.8  98.2
 2.58
0.62
Which of the above temperatures is usual or unusual and why?
ii. is unusual because it is a z-value greater then 2 or you can say 99.8 is more then two standard deviation
from the mean i.e. x  2s  98.2  2(0.62)  99.44
i. Is usual, z is within two sd.
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VI.
Show all work step by step. Find the mean, mode, variance and standard deviation of the
following sample data. ( 5 points)
Heights (in) of men are: 71, 66, 72, 69, 68, 69
Mean: _
71  66  72  69  68  69
 69.1667
6
Mode:_____69___
Variance:__ s
x
71
66
72
69
68
69
 (x  x)

n 1
2

22.8334
 4.5667
5
(x  x)2
3.3610
10.0280
8.0276
0.0278
1.3612
0.0278
 (x  x)
2
 22.8334
Standard Deviation:__ s 2  4.5667  2.137 _
Extra credit (0.5 points each, 3 points total)
Give a specific example of the fallowing:
1. Nominal data____________________
2. Ordinal data_____________________
3. Interval data_____________________
4. Ratio level data_________________
What measure of center is most sensitive to extreme values ________________
What is the range rule of thumb? ___________________
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