It is estimated that 35% of households own a riding lawn mower. A sample of 10 households is studied. What is the standard deviation of the number of households who own a riding lawn mower?
A) 3.5
B) 1.5083
C) 2.275
D) 10

Question

Quizplus · Accepted Answer

We can use the formula for standard deviation of a binomial distribution: 
SD = √[np(1-p)] 
where n is the sample size and p is the probability of success (in this case, owning a riding lawn mower). 
Plugging in the values, we get: 
SD = √[10(0.35)(0.65)] 
SD ≈ 1.5083 
Therefore, the standard deviation of the number of households who own a riding lawn mower is approximately 1.5083.

It Is Estimated That 35% of Households Own a Riding