Download Business Math

Business Math
Exam Chapter 10
Name____________________________________
Group
Period ___________________
10.1 -2
Use the following data for all the following questions in 10.1:
74
133
4
127
20
30
103
27
139
118
138
121
149
132
64
141
130
76
42
50
95
56
65
104
4
140
12
88
119
64
a) Make a Frequency Distribution Table using 6 intervals
INTERVAL TALLY
0 - 24
b) Find the grouped mean,
FREQUENCY MIDPOINT
25 - 49
50 - 74
75 - 99
c) Find the modal class.
100 - 124
125 – 149
Construct a HISTOGRAM and a FREQUENCY POLYGON
y
x
Is the Histogram Left Skewed, Right Skewed, Nornal, or Uniform? __________________________
x
10.3
2) A company often uses “Preformance Ratings” to give promotions and raises and also to fire employees.
A Grocery Store checks the time spent in a check-out line ( in minutes) for 13 randomly selected customers
during the store’s busiest time:
One person was chosen in each of 13 checkout lines serviced by different employees.
The minutes the customer waited in the line was measured.
4.6
8.5
6.1
7.8
10.9
9.3
11.4
5.8
9.7
8.8
6.7
13.2
10.9
a)
Find the Range: ______________________
b)
Find the Median:
c)
Is there a Mode? ___________ If, YES, what is it? _____________________
d)
Find the mean:
e)
Find the standard deviation (squared) (sample) s =
f)
Which time(s) lie outside 1 standard deviation of the mean.
___________________
x
Below ___________________ Above _________________________
3)
Find the Mean and the Standard Deviation for the scores obtained on recent Calculus Test.
SCORE
FREQUENCY
90 - 99
6
80 - 89
9
70 - 79
30
60 - 69
15
50 - 59
3
Mean, x ,
Standard Deviation ,
s =,
10.4
4)
Find the z – score for the following situations.
a)
Grade of 74 on a test with mean 82
and standard deviation 6.5
5)
Find the percent of the area under a normal curve between the indicated numbers.
Sketch and shade your answer.
A time of 10.8 seconds in a race
with μ = 10.1 sec. and σ = .51
y
y
x
a) between the mean and z = 1.4
6)
b)
x
b) between z = -.64 and z = 1.75
A certain brand of 100 – watt light bulb has a mean life of 750 hours and a standard
devieation of 50 hours. Assuming that the lives of these bulbs are normally distributed,
what proportion of the bulbs will burn
a)
at least 820 hours
b)
between 600 and 775 hours
10.5
7)
Experinental data indicates that the cure rate of a new drug is 85% . If the drug is given
to 100 patients, find the probability that at least 90 of them will be cured.
Use The Normal Distribution as an approximation for the Binomial .
8)
Actuarial tables indicate an accidental death rate in the United States of 56 persons per 100,000.
If an insurance company covers 500,000 individuals for accidental death benefits, what is the
probability that the number of claims in a year will be between 260 and 300 (inclusive)?
Use The Normal Distribution as an approximation and define success as “filing a claim.”
9)
Use the following data for all the following questions
74
133
4
127
20
30
103
27
139
118
138
121
149
132
64
141
130
76
42
50
95
56
65
104
4
140
12
88
119
64
Find the Median and create a BOX PLOT for the data.