Answer: a. 2
Step-by-step explanation:
According to the Empirical rule, when data is normally distributed then 95% of the lies within 2 standard deviations from mean.
Given: The distribution of the heights of students in a large class is roughly bell-shaped ( i.e. Normally distributed).
The average height is 68 inches, and approximately 95% of the heights are between 62 and 74 inches.
Then, by Empirical rule, 68 -2(standard deviations) =62 [lower limit]
⇒ 2(standard deviations)= 68-62 = 4
⇒ standard deviations=2
Hence, correct option is a. 2
Answer:
B-3
Step-by-step explanation:
According to the empirical rule, roughly 95% of the distribution is within 2 standard deviations of the mean.
The mean is 68. The distance from 62 to 68 is 6 inches
68-62=6
Cut that in half to get 6/2 = 3
So the standard deviation is 3
