NEW
Font size
S
M
L
XL
WorksheetsThe normal distribution
Total questions: 11
Worksheet time: 31mins
Name
Class
Date
1.
What is the the total area under the standard normal distribution curve?
a)
100
b)
25
c)
.5
d)
1
2.
If 10 is added to every value in a set of data, what will happen to the value of the mean?
a)
it will increase by 10
b)
it will decrease by 10
c)
it will stay the same
d)
it will both increase and decrease
3.
If 10 is added to every value in a set of data, what will happen to the value of the standard deviation?
a)
it will increase
b)
it will decrease
c)
it will stay the same
d)
it will both increase and decrease
4.
Which is NOT true about the standard normal distribution?
a)
It is bell-shaped.
b)
It is unimodal.
c)
The mean is 0 and the standard deviation is 1.
d)
It is asymmetrical.
5.
The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days.
About what percent of the products last between 12 and 15 days?
About what percent of the products last between 12 and 15 days?
a)
68%
b)
34%
c)
16%
d)
2.5%
6.
The mean life of a tire is 30,000 km. The standard deviation is 2000 km.
Then, 68% of all tires will have a life between ___________ km and __________ km.
Then, 68% of all tires will have a life between ___________ km and __________ km.
a)
28,000 km and 32,000 km.
b)
24,000 km and 34,000 km.
c)
26,000 km and 34,000 km.
d)
27,000 km and 31,000 km.
7.
Find P (-1.26 < z < 3.25).
a)
0.0047
b)
0.9204
c)
0.8956
d)
0.4981
8.
The mean number of accidents a week at a company is 6.4 with a standard deviation of 1.5. What proportion of weeks would you expect to have less than 5 accidents?
a)
0.6915
b)
0.1753
c)
0.8238
d)
-0.93
9.
The scoring of modern IQ is such that Intelligence Quotients (IQs) have a normal distribution of μ= 100 and 𝞂 = 15.
Mensa International is a non-profit organization that accepts only people with IQ score within the top 2%. What integer level of IQ qualifies one to be a member of Mensa?
Mensa International is a non-profit organization that accepts only people with IQ score within the top 2%. What integer level of IQ qualifies one to be a member of Mensa?
a)
130
b)
131
c)
145
d)
120
10.
A manufacturer contracts to supply ball bearings with diameters between 24.60mm and 25.4mm. Product analysis indicates that the ball bearings manufactured have diameters that are normally distributed with a mean of 25.10mm and a standard deviation of .20mm. What percentage of ball bearings fail to satisfy the contract specifications?
a)
92.7%
b)
7.3%
c)
48.2%
d)
33.2%
11.
The average number of calories in a 1.5-ounce chocolate bar is 225. Suppose that the distribution of calories is approximately normal with a σ of 10. Find the probability that a randomly selected chocolate bar will have between 200 and 220 calories.
a)
0.9876
b)
0.3023
c)
0.0098
d)
0.3320
Reset
