The owner of the West End Kwick Fill Gas Station wishes to determine the proportion of customers who pay at the pump using a credit card or debit card. He surveys 100 customers and finds that 80 paid at the pump. a. Estimate the value of the population proportion. b. Develop a 95% confidence interval for the population proportion. c. Interpret your findings

n = 100 customers

X = 80 who paid at the pump

A) the sample proportion = p = X / n = 80 / 100 = 0.8

we can definitely state that 80% of the customers paid at the pump.

B) if we want to determine the 95% confidence interval:

z (95%) = 1.96

confidence interval = p +/- z x √{[p(1 - p)] / n}

0.80 +/- 1.96 x √{[0.8(1 - 0.8)] / 100}

0.80 +/- 1.96 x √{(0.8 x 0.2) / 100}

0.80 +/- 1.96 x √{(0.8 x 0.2) / 100}

0.80 +/- 1.96 x 0.4

0.80 +/- 0.0784

confidence interval = (0.7216 ; 0.8784)

C) We can estimate with a 95% confidence that between 72.16% and 87.84% of the customers pay at the pump.

the page presents four different kinds of threats that volcanoes pose and what to do before, during, and after an eruption.

where is the graph?