Question

in one town, 66% of adults have health insurance. what is the probability that 4 adults selected at random from the town all have health insurance? round to the nearest thousandth if necessary
a. 0.001
b. 0.66
c. 2.64
d. 0.19

Explanation:

Step1: Convert percentage to decimal

$86\% = 0.86$

Step2: Calculate joint probability

Since each adult's insurance status is independent, raise the single probability to the 4th power:
$P = 0.86^4$

Step3: Compute the value

$0.86^4 = 0.86\times0.86\times0.86\times0.86 = 0.54700816$

Step4: Round to nearest thousandth

$0.54700816 \approx 0.55$

Answer:

B. 0.55