1
A fast-food restaurant gave a “Customer Satisfaction Survey” in which 1500 customers rated
how satisfied they were with service. The results are shown below as a table.
Rating Frequency
Extremely Satisfied 234
Sat
...
1
A fast-food restaurant gave a “Customer Satisfaction Survey” in which 1500 customers rated
how satisfied they were with service. The results are shown below as a table.
Rating Frequency
Extremely Satisfied 234
Satisfied 443
Neutral 246
Dissatisfied 203
Extremely Dissatisfied 374
The relative frequency of people who were dissatisfied with the service is __________.
13.5%
29.5%
20.3%
38.5%
2
The formula for the standard deviation of a sample is:
Select the true statement for the following data set that has a mean of 8:
4, 6, 6, 6, 9, 9, 12, 12
Answer choices are rounded to the hundredths place.
The variance is 2.98 and the standard deviation is 8.86.
The variance is 8.86 and the standard deviation is 7.50.
The variance is 8.86 and the standard deviation is 2.98.
The variance is 7.50 and the standard deviation is 2.98.
3
Let x stand for the number of minutes spent waiting in line for a rollercoaster at an
amusement park. 81 people are sampled at a time. The sample mean is 18 minutes and the
sample standard deviation is 0.5 minutes.
What is the standard deviation of the population?
18
4.5
0.5
2
4
Mike's electronics store sold the following number of cellphones on each of the seven days of
a week.
Day Cell Phones Sold
Sunday 12
Monday 10
Tuesday 9
Wednesday 5
Thursday 14
Friday 10
Saturday 10
The mean number of cell phones sold by the store for the week was __________.
5 phones
70 phones
9 phones
10 phones
5
The average daily rainfall for the past week in the town of Hope Cove is normally distributed,
with a mean rainfall of 2.1 inches and a standard deviation of 0.2 inches.
If the distribution is normal, what percent of data lies between 1.9 inches and 2.3 inches of
rainfall?
34%
99.7%
68%
95%
6
Choose the statement that correctly describes a normal distribution.
The approximate percent of values lying within two standard deviations of the mean is
47.5%.
Approximately 68% of the values are greater than the mean value.
The approximate percent of values lying within three standard deviations of the mean is
49.85%.
Approximately 68% of the values lie within one standard deviation of the mean.
7
Hannah noted the height of each student in her class and found that the mean height of the
students is 56 inches, with a standard deviation of 1.2 inches. The height of one of the
students, James, is 59 inches.
What is the z-score for James' height?
-3.6
2.5
3.6
-2.5
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