Download Math109Quiz1Fall2011

North Seattle Community College
Fall Quarter 2011
ELEMENTARY STATISTICS
2618 MATH 109 - Section 05,
Chapter 1 and 2 - Practice Quiz 1
STUDENT NAME: __________________________
10th October 2011
QUIZ SCORE: ______________________________
Question 1
Identify the population and/or the sample in the following. Describe the data set. Also decide
whether the numerical values describe population parameters or sample statistics:
a. A recent survey of a sample of 750 college students reported that the average weekly
income for students is $400.
b. The 2182 students who accepted admission offers to Northwestern University in 2009
have an average SAT score of 1442.
Question 2
If the mean of numbers 28, x, 42, 78 and 104 is 62, then what is the mean of 128, 255,
511, 1023 and x?
Question 3
Suppose you are given a data set to analyze. The data consist of 1000 observations on one
variable, the height of the subject being interviewed. Assume half the subjects are male
and half are female. The sample mean height of the males is greater than the sample mean
height the females, while the sample standard deviation of the females is greater than the
sample standard deviation of the males. Both histograms are approximately symmetric
and bell-shaped. Draw two histograms, one for males and one for females, to illustrate
these facts?
Question 4
John received an 86 on a test whose class mean was 70 with a standard deviation of 5.
Samantha received a 75 on a test whose class mean was 60 with a standard deviation of 4.
Which student had relatively the better test score?
Question 5:
The following data represents the ages of all the people that participated in a charity
obstacle race from a small village: (15, 15, 15, 17, 17, 17, 17, 17, 19, 19, 19, 19, 23, 23, 23,
29, 29)
I. Complete the following frequency table:
x
Freque
ncy, f
Relative
frequency
Cumulative
Frequency
15
17
19
23
29
II. Compute the following:
a. Mean, Median and Mode
b. Range, Standard deviation and Variance
c. Five number summary and IQR
d. Find the age range in which at least 75% of the data lies. Use Chebychev’s
theorem since the distribution is not bell-shaped and symmetric.
(Hint: when k=2, proportion of the data that lies within the 2 standard
deviations is 75%)