Question

One hundred teachers attended a seminar on mathematical problem solving. The attitudes of representative sample of 12 of the teachers were measured before and after the seminar. A positive number for change in attitude indicates that a teacher's attitude toward math became more positive. The twelve change scores are as follows.

4; 7; −1; 1; 0; 5; −2; 2; −1; 6; 5; −3

1. What is the mean change score? (Round your answer to two decimal places.)

2. What is the standard deviation for this sample? (Round your answer to two decimal places.)

3. What is the median change score? (Round your answer to one decimal place.)

4. Find the change score that is 2.2 standard deviations below the mean. (Round your answer to one decimal place.)

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A sample of 100 clients of an exercise facility was selected. Let X = the number of days per week that a randomly selected client uses the exercise facility.

X	Frequency
0	3
1	14
2	31
3	28
4	10
5	7
6	7

1. Find the number that is 1.5 standard deviations BELOW the mean. (Round your answer to three decimal places.)

Answer 1

Solution:

1. What is the mean change score? (Round your answer to two decimal places.

2. What is the standard deviation for this sample? (Round your answer to two decimal places.)

Answer: The formula for finding the standard deviation is:

3. What is the median change score? (Round your answer to one decimal place.)

Answer: We have to first sort the data in ascending order as:

-3,-2,-1,-1,0,1,2,4,5,5,6,7
The median is:

  

  

4. Find the change score that is 2.2 standard deviations below the mean. (Round your answer to one decimal place.)

Answer: The change score that 2.2 standard deviations below the mean is:

A sample of 100 clients of an exercise facility was selected. Let X = the number of days per week that a randomly selected client uses the exercise facility.

X	Frequency
0	3
1	14
2	31
3	28
4	10
5	7
6	7

1. Find the number that is 1.5 standard deviations BELOW the mean. (Round your answer to three decimal places.)

The mean and standard deviation of the given data is:

Therefore, the number that is 1.5 standard deviations BELOW the mean is: