A test worth 100 points was given to a class with the following results:
|
Mid point(X)
|
Interval
|
Frequency (f)
|
|
94.5
|
89.5-99.5
|
9
|
|
84.5
|
79.5-89.5
|
8
|
|
74.5
|
69.5-79.5
|
17
|
|
64.5
|
59.5-69.5
|
6
|
|
54.5
|
49.5-59.5
|
3
|
a. Fill in the midpoint column and the relative frequency column in the above table.
b. Draw the histogram.
c. Calculate the population mean and population standard deviation.
d. What proportion of the class score 79.5 or above?