Question

suppose a class obtained the following scores on a test.
score frequency
90 1
80 6
70 10
60 3
50 2
40 3
what is the mean?

Explanation:

Step1: Calculate total score

To find the total score, we multiply each score by its frequency and sum them up.
For score 90: $90\times1 = 90$
For score 80: $80\times6 = 480$
For score 70: $70\times10 = 700$
For score 60: $60\times3 = 180$
For score 50: $50\times2 = 100$
For score 40: $40\times3 = 120$
Now sum these products: $90 + 480 + 700 + 180 + 100 + 120 = 1670$

Step2: Calculate total number of students

The total number of students is the sum of all frequencies.
$1 + 6 + 10 + 3 + 2 + 3 = 25$

Step3: Calculate the mean

The mean is the total score divided by the total number of students.
Mean = $\frac{1670}{25} = 66.8$

Answer:

66.8