Clara recorded 50 numerical observations on a certain variable and then calculated the mean and the standard deviations for the observations. To help decide whether a normal model is appropriate, she created the following chart
a
b
с
d
e
X-2s
X-S
X+S
X + 2s
In Clara's chart, the letters a, b, c, d, and c represent the number of observations falling in each interval. Which of the following list of counts for a, b, c, d, and e, respectively, is the best indicator that the variable can be
modeled with a normal approximation?
А
1.7,34,7,1
1,10,28, 10,1
С
2,8, 30, 8,2
D
2, 4, 38, 4,2
E
5,5, 30,5,5