Question

Q1: A student has gotten the following grades on his tests: 82, 90, 66, and 83. He wants an 83 or better overall. What is the minimum grade he must get on the last test in order to achieve that average?

..

Q2: A distribution of 6 scores has a median of 24. If the highest score

        Increases 3 points, the median will become ___________.

21

21.5

24

cannot be determined without additional information.   

none of these

..

Q3: compute the mean of the following data:

               X      Freq.

            ----------------

               0         4

               1         3

               2         1

               3         0

               4         1

.

.

Q4: The standard deviation of a group of scores is 10. If 5 were subtracted from each score, the standard deviation of the new scores would be

a. 2   

b. 10/25   

c. 5      

d. None of these.

.

Q5: The variance of the following sample of five numbers

        3, 3,3,3,3 is:

0  

3    

9  

11.25

Answer 1

Q1) Solution: the minimum grade he must get on the last test in order to achieve that average is 94

Consider x and use average formula here,

=> x=94

Q2) Solution: Option c) is correct.

A distribution of 6 scores has a median of 24. If the highest score

        Increases 3 points, the median will become 24

Median is not affected by increasing largest number in given scores.

Q3) Solution:

X	F	X*F
0	4	0
1	3	3
2	1	2
3	0	0
4	1	4
Total	9	9

Mean

=9/9

=1

Q4) Solution: d. None of these.

Standard deviation is 10.

It is not affected by subtracting 5 from each score.

Q5) Solution: Option A) is correct. 0

Variance of constant is always 0