Question

Lifetimes of a certain brand of lightbulbs is known to follow a right-skewed distribution with mean 24 months and standard deviation 2 months. Suppose we take a sample of size 1500 from this distribution, and create a histogram. We expect this histogram to be...

Select one:

a. Normal with a mean of approx. 24 months and a standard deviation of approx. 2 months.

b. Right-skewed with a mean of approx. 24 months and a standard deviation of approx. 2 months.

c. Normal with a mean of approx. 24 months and a standard deviation of approx. 0.0013 months.

d. Normal with a mean of approx. 24 months and a standard deviation of approx. 0.0516 months.

e. Right-skewed with a mean of approx. 24 months and a standard deviation of approx. 0.0516 months.

Answer 1

Solution :

Given that ,

mean = = 24

standard deviation = = 2

n = 1500

=   = 24

= / n = 2 / 1500 = 0.0516

d. Normal with a mean of approx. 24 months and a standard deviation of approx. 0.0516 months