answer question 3 and explain how you find observed frequency and what it would be for all of them

I Calculate and record the observed frequencies of sample means in cach of the classes indicated in the following table. Note that interval endpoints are midpoint + 0.5*width and the interval midpoint is average of two endpoints. Use 9.31, 9.61, 9.91, 10.21, 10.51 and 10.81 as the "bin" boundaries for the Excel HISTOGRAM procedure. trase Class interval Midpoint Expected frequency Observed Frequency < 9.31 8.3794 9.31 - 9.61 9.46 13.3902 9.61 - 9.91 9.76 21.0881 9.91 - 10.21 10.06 23.4181 10.21 10.51 10.36 18.3379 10.51 - 10.81 10.66 10.1248 > 10.81 5.2616 3. What was the observed frequency of sample means that fell between 9.91 and 10.21 ?