Exhibit 7-2
A random sample of 10 examination papers in a course, which was given on a pass or fail basis, showed the following scores.
-Refer to Exhibit 7-2. The point estimate for the standard deviation of the population is
A)419.43
B)20.48
C)75
D)750

Question

Exhibit 7-2
A random sample of 10 examination papers in a course, which was given on a pass or fail basis, showed the following scores. 
-Refer to Exhibit 7-2. The point estimate for the standard deviation of the population is
A)419.43 
B)20.48 
C)75 
D)750

Quizplus · Accepted Answer

To find the point estimate for the standard deviation of the population, we use the formula:
s = √[(Σ(x - x̄)²)/(n - 1)]
Plugging in the given values, we get:
s = √[(Σ(x - x̄)²)/(n - 1)]
s = √[(17.6 + 51.84 + 5.76 + 46.24 + 11.56 + 7.84 + 2.56 + 22.09 + 75.69 + 33.64)/(10 - 1)]
s = √[275.48/9]
s = √30.61
s = 5.53
Therefore, the point estimate for the standard deviation of the population is 5.53, which corresponds to choice B.

Exhibit 7-2 A Random Sample of 10 Examination Papers in a Course