Question

: The CAT scores of 60 students are summarized below:

Class 40-50 50-60 60-70 70-80 80-90 90-100

Frequency 10 8 12 15 10 5

Calculate the sample mean, the sample variance and the standard deviation for the grouped data.​

Answer 1

Answer:

Step-by-step explanation:

Answer 2

Step-by-step explanation:

Here is the correct answer. Hope this will help