Question

for data with a bell - shaped distribution, we are promised (a) (b) of the data is within 3 standard deviations of the mean.
(a) choose the correct choice for a word in blank (a) in the above statement.
a. at most
b. exactly
c. about
d. at least
(b) choose the correct choice for a percentage in blank (b) in the above statement.
a. 68%
b. 75%
c. 89%
d. 95%
e. 99.7%

Explanation:

For a bell - shaped (normal) distribution, the empirical rule states that about 99.7% of the data lies within 3 standard deviations of the mean. The word used is "about".

Answer:

(a) C. about
(b) E. 99.7%