Answer:
a.) Minimum test score = 41
Maximum test score = 95
b.)An approximate value of the standard deviation is 9.
Step-by-step explanation:
The given set of test scores is approximately bell shaped.
The mean of the test scores, = 68
The range of the data set = 54.
a.) i.) Minimum test score =
ii.) The maximum test score =
b.) From the 68-95-99.7 rule, also known as the Empirical rule, tell us that an approximation of the range is 3 standard deviations either way from the mean. So from this rule we can say that the minimum can also be found from and the maximum can also be approximated as
.
From the above we can say that the range can be written as
∴
∴
Therefore an approximate value of the standard deviation is 9.