Question

The National Coffee Association reported that of U.S. adults drink coffee daily. A random sample of U.S. adults is selected. Round your answers to at least four decimal places as needed.
Required:
a. Find the mean μ.
b. Find the standard deviation σ.
c. The standard deviation σ.

Answer 1

The question is incomplete. The complete question is :

The National Coffee Association reported that 62% of U.S. adults drink coffee daily. A random sample of 225 U.S. adults is selected. Round your answers to at least four decimal places as needed.

Required:

a. Find the mean μ.

b. Find the standard deviation σ.

c. The standard deviation σ.

Solution :

a). Percentage of the US adults who drinks coffee daily = 62%

Therefore, the mean, μ = 0.62

b). We know, p = μ = 0.62

And n = 225

Therefore, the standard deviation is given by :

$\sigma=\sqrt{\frac{p\times (1-p)}{n}}$

 $=\sqrt{\frac{0.62\times (1-0.62)}{225}}$

 $=\sqrt{\frac{0.62\times 0.38}{225}}$

 $=0.0324$

c). Standard deviation, σ = 0.0324