Question

1. Find the GPA of the following grades.

A student received the following grades.

C     in Math 120   worth 4 credits.

B      in English 125 and worth 3 credits

A in Chem 102 and worth 5 credits.

2. According to Empirical Rule, the mean is 35 and the standard deviation is 3.

1. 68 % of the data lie between what values.
2. 95% of the data lie between what values
3. 99.7 % of the data lie between what values

4. Given the following data. Find the mean, variance , standard deviation of the population.

X     ( x -   µ )    (x - µ )²

2

5

6

Answer 1

(1)

Answer is:

3.083

Explanation:

From the given data, the following Table is calculated:

Course	Credit	Grade	Grade Point
Math 120	4	C (2 Grade Points)	4 X 2= 8
English 125	3	B (3 Grade Points)	3 X 3 = 9
Chem 102	5	A (4 Grade Points)	5 X 4 = 20
Total	12	9	37

Overall Grade Point Average (GPA) = Total Grade Point/Total Credits

                                                  = 37/12

                                                 = 3.083

(2)

= 35

= 3

(i)

68 % of the data lie between :

(ii)

95% of the data lie between

(iii)

99.7 % of the data lie between

(3)

Answers are:

mean = 4.3333

variance = 2.8889

standard deviation = 1.6997

Explanation:

(i)

= Population Mean = 13/3 = 4.3333

(ii)

x	(x - )	(x - )2
2	- 2.3333	5.4444
5	0.6667	0.4444
6	1.6667	2.7778
Total =		8.6667

So,

Population Variance () is given by:

(iii)

Population Standard Deviation () is given by: