Question

4. The following calculator display presents the class midpoints and corresponding class frequencies of a grouped data of a randomly selected sample respectively stored in L1 and L2

L1 (Class Mid Points)	L2 (Class Frequencies)
35	7
50	16
65	29
80	20
95	8

Find the sample size, class width, sample mean, standard deviation rounded to three decimal places, and the exact value of the sample variance in reduced fraction.

Please show me how to arrive at the answers. I'm struggling with finding these answers with only the midpoints and the frequencies. I was taught in class to do it with the class limits already given.

Answer 1