Question

Ninety-five percent of all marigold flowers have a height between 10.9cm and 119.0cm and their height is normally distributed what’s the mean?

Answer 1

Answer: mean = 64.95

Explanation:

According to the Empirical rule , 95% of the population lies with 2 standard deviations from the mean when data is normally distributed.

Given: 95% of all marigold flowers have a height between 10.9 cm and 119.0 cm.

If height is normally distributed , then

Mean - 2 standard deviation = 10.9 (i)

Mean + 2 standard deviation = 119.0 (ii)

Add (i) and (ii), we get

2 Mean = 10.9+119.0

⇒ 2 Mean = 129.9

⇒ Mean = 64.95 [divide both sides by 2]

So, mean = 64.95