UNIT 2- MILESTONE 2 INTRO TO STATS
In which of these cases should mode be used?
When the data has extreme values
When the data is represented using ratio scale
When the data is represented using interval scale
When the data is qualitative and we talk about the most frequent category - correct answer-If
the data is qualitative, it is only descriptive. In this case, the mode is a good measure since
the mode examines the most frequently occurring value. The data can be non-numeric.
Let x stand for the percentage of an individual student's math test score. 64 students were
sampled at a time. The population mean is 78 percent and the population standard deviation
is 14 percent.
What is the standard deviation of the sampling distribution of sample means?
0.22
14
64
1.75 - correct answer-The standard deviation of the sampling distribution, , is equal to the
standard deviation of the original population, , divided by the square root of the sample size,
. If the standard deviation of the population is 14 and the sample size is 64, then the
standard deviation of the sampling distribution is: 1.75
Sara wonders what percentage of her students answered at least half of the quiz questions
incorrectly.
The cumulative frequency of students who earned a score of 20 or lower on the quiz is
__________. - correct answer-To get cumulative frequency of 20 or less, we simply add up
any bin that has the number 20 or less, such as the bin that shows scores of 1-5, 6-10,
11-15, and 16-20.
The dot plot below shows the number of songs Carly downloaded over 15 successive
weekends
What is the greatest number of songs downloaded?
8
10
9
5 - correct answer-The dotplot is a number line that shows the number of items at each
value, which is designated with an X. So the largest value we can see is at 10.
The manager went over the sales of mobile phones at the store and found that the mean
sale was 45, with a standard deviation of 4. On a particular day, 52 mobile phones were
sold.
What is the z-score of the sale of mobile phones on that day?
28
-28
1.75
-1.75 - correct answer-Recall that the z-score can be calculated with the following formula:
In which of these cases should mode be used?
When the data has extreme values
When the data is represented using ratio scale
When the data is represented using interval scale
When the data is qualitative and we talk about the most frequent category - correct answer-If
the data is qualitative, it is only descriptive. In this case, the mode is a good measure since
the mode examines the most frequently occurring value. The data can be non-numeric.
Let x stand for the percentage of an individual student's math test score. 64 students were
sampled at a time. The population mean is 78 percent and the population standard deviation
is 14 percent.
What is the standard deviation of the sampling distribution of sample means?
0.22
14
64
1.75 - correct answer-The standard deviation of the sampling distribution, , is equal to the
standard deviation of the original population, , divided by the square root of the sample size,
. If the standard deviation of the population is 14 and the sample size is 64, then the
standard deviation of the sampling distribution is: 1.75
Sara wonders what percentage of her students answered at least half of the quiz questions
incorrectly.
The cumulative frequency of students who earned a score of 20 or lower on the quiz is
__________. - correct answer-To get cumulative frequency of 20 or less, we simply add up
any bin that has the number 20 or less, such as the bin that shows scores of 1-5, 6-10,
11-15, and 16-20.
The dot plot below shows the number of songs Carly downloaded over 15 successive
weekends
What is the greatest number of songs downloaded?
8
10
9
5 - correct answer-The dotplot is a number line that shows the number of items at each
value, which is designated with an X. So the largest value we can see is at 10.
The manager went over the sales of mobile phones at the store and found that the mean
sale was 45, with a standard deviation of 4. On a particular day, 52 mobile phones were
sold.
What is the z-score of the sale of mobile phones on that day?
28
-28
1.75
-1.75 - correct answer-Recall that the z-score can be calculated with the following formula:
