Nutrition animals The mouse weights in grams of a random sam

?Nutrition: animals. The mouse weights? (in grams) of a random sample of 100 mice involved in a nutrition experiment? are:

Find the standard deviation of the weight of the mice in grams

Nutrition: animals. The mouse weights (in grams) of a random sample of 100 mice involved in a nutrition experiment are: Interval 1.5 43.5 43.5-45.5 45.5 -47.5 7.5 49.5 49.5 51.5 16 Frequency 2 26 13 Interval 1.5 53.5 53.5 55.5 55.5 57.5 57.5 59.5 Frequency 15 13 a. Find the mean of the weight of the mice gms (Type an integer or a decimal. Round to two decimal places.)

Solution

Find midpoint (x) of each class interval :

1) 42.5 ----2 ---- 42.5*2 = 85

2) 44.5---- 7 ----44.5*7 = 311.5

3) 46.5 ---- 13 ---- 604.5

4) 48.5 ---- 26---- 1261

5) 50.5 ---- 16---- 808

6) 52.5 ----- 15---787.5

7) 56.5 ----13 ----734.5

8) 58.5 --- 7 -----409.5

Add all the products ( f*X) =   85 + 311.5 + .........734.5 +409.5 = 5001.5

Mean = Summation (f*x)/Summation(f) = 5001.5/100 = 50.01