Font size
S
M
L
XL
WorksheetsNormal Distribution and Probability
Total questions: 25
Worksheet time: 2hrs 14mins
Name
Class
Date
1.
6.3 z-scores: The temperature is recorded at 60 airports in a region. The average temperature is 67 degrees Fahrenheit with a standard deviation of 5 degrees. Given a z-score of -0.2, what is the temperature? (Use formula, solve for x)
a)
65
b)
68
c)
67
d)
66
2.
6.3 Non-Standard Normal Distribution: A bank's loan officer rates applicants for credit. The ratings are normally distributed with a mean of 200 and a standard deviation of 50. Find P60, the score which separates the lower 60% from the top 40%.
a)
187.5
b)
212.7
c)
207.8
d)
211.3
3.
6.7 Binomial: There is an 80% chance that an employer will check the educational background of a job applicant. Sixty-four job applicants are randomly selected. What is the probability that more than 50 applicants will have their background checked?
a)
0.702
b)
0.528
c)
0.673
d)
0.587
4.
6.2: Standard Normal Distribution (mean is 0 and standard deviation is 1). Find the score that separates the lowest 98% from the highest 2%.
a)
- 2.05
b)
2.05
c)
-1.95
d)
1.95
5.
6.2: Uniform distribution: Suppose your phone battery can last anywhere between 2 hours and 8 hours depending on use. If the amount of time it lasts is distributed uniformly, what is the probability that the battery lasts less than 4 hours?
a)
1/6
b)
1/4
c)
1/3
d)
1/2
6.
6.2: Standard Normal Distribution (mean is 0 standard deviation is 1). For a randomly selected subject, find the probability of a score between 1.37 and 2.42.
a)
0.078
b)
0.785
c)
0.223
d)
0.023
7.
6.3: Non-Standard Normal Distribution. IQ scores are normally distributed with mean 100 and standard deviation 15. Find the probability of randomly selecting an IQ score above 90.
a)
0.683
b)
0.748
c)
0.715
d)
0.796
8.
6.3: Non-Standard Normal Distribution. IQ scores are normally distributed with a mean of 100 and standard deviation 15. Find the IQ score separating the bottom 85% from the top 15%.
a)
135
b)
125
c)
120
d)
115
9.
6.5 CLT: Red blood cell counts of women are normally distributed with a mean of 4.577 and a standard deviation of 0.382. Find the probability that one randomly selected woman has a red blood cell count above 5.4.
a)
0.150
b)
0.0156
c)
0.215
d)
0.0237
10.
6.5 CLT: Red blood cell counts of women are normally distributed with a mean of 4.577 and a standard deviation of 0.382. What percentage of women have red blood cell counts in the normal range from 4.2 to 5.4?
a)
82.3%
b)
77.8%
c)
72.6%
d)
68%
11.
6.5 CLT: Red blood cell counts of women are normally distributed with a mean of 4.577 and a standard deviation of 0.382. If 25 women are randomly selected, find the probability that the mean of their red blood cell counts is less than 4.444.
a)
0.409
b)
0.0409
c)
0.368
d)
0.0368
12.
6.7 Binomial: Use the continuity correction and describe the region of the normal distribution that corresponds to the probability of exactly 44 green marbles.
a)
The area between 43.5 and 45.5
b)
The area between 43.5 and 44
c)
The area between 43.5 and 44.5
d)
The area between 44 and 44.5
13.
6.7 Binomial: Estimate the indicated probability by using the normal distribution as an approximation to the binomial distribution with n = 18 and p = 0.30. Estimate P(exactly 6).
a)
0.124
b)
0.102
c)
0.158
d)
0.194
14.
6.7 Binomial: For the binomial distribution with the given values for n and p, state whether or not it is suitable to use the normal distribution as an approximation: n = 24 and p = 0.6
a)
Yes - normal approximation is suitable.
b)
No - normal approximation is not suitable.
15.
6.2 Uniform distribution: Using the uniform density curve shown, what is the probability that the random variable x has a value greater than 5?
(Probability = Area of a Rectangle)
(Probability = Area of a Rectangle)
a)
0.325
b)
0.500
c)
0.250
d)
0.375
16.
6.3 z-scores: Scores on a history test have an average of 80 with a standard deviation of 6. What is the z-score for a student who earned a 75 on the test? (Use the formula solve for z)
a)
-0.83
b)
0.83
c)
-0.17
d)
0.17
17.
6.6 Histogram: Can the mean of this sample be treated as a value from a population having a normal sample? Why or why not?
50 55 61 67 70 53 57 64 68 59
50 55 61 67 70 53 57 64 68 59
a)
Yes, the histogram shows a normal distribution.
b)
No, the histogram is not normal and n < 30.
c)
No, the histogram is not normal and n > 30.
d)
Yes, the histogram is not normal and n > 30.
18.
Women’s heights have a mean of 63.6 in. and a standard deviation of 2.5 inches. A woman is in the 98th percentile. How tall is the woman?
a)
58.5 in
b)
66.8 in
c)
61.5 in
d)
68.7in
19.
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 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 level of IQ qualifies one to be a member of Mensa?
a)
115
b)
130.75
c)
145
d)
120
20.
In a weightlifting competition, the amount that the competitors can lift is normally distributed with μ = 196 kg and σ = 11 kg. Only the top 10% of all competitors will be able to advance to the next phase of the competition. What amount must a competitor lift in order to move into the next phase of the competition?
a)
206 kg
b)
210 kg
c)
182 kg
d)
222 kg
21.
The z-score represents.....
a)
the amount of standard deviations a data value is above or below the mean.
b)
the percentile the data value is above or below the mean.
c)
the amount of standard deviations a data value is above or below the median.
d)
the percent the data value is above or below the mean.
22.
The percentile represents the....
a)
percent of data values that are below.
b)
percent of data values that are above.
c)
number of data values that are below.
d)
number of data values that are below.
23.
Find the area under the standard normal curve to the right of z = -2.67.
a)
0.0869
b)
0.9962
c)
0.0008
d)
0.1234
24.
A sample should be
a)
representative of only middle school students only
b)
a very large group
c)
representative of the population
d)
representative of people who volunteer
25.
Which of the following are unbiased estimators?
a)
proportion (p-hat)
b)
median
c)
range
d)
mean (x-bar)
e)
variance
Reset
