You randomly select 16 restaurants and measure the temperature of the coffee sold at each. The sample mean temperature is 162 degrees with a standard deviation of 10 degrees. Assuming that the temperature is approximately normally distributed, a 95% confidence interval for the mean temperature is:

( 157.1 , 166.9 )

Step-by-step explanation:

95% Confidence Interval is the range around sample mean(s), which is 95 certain to contain population parameter (population mean).

Formula : x' + z (s / √n) ,

where x' =  sample mean = 162 ; sample standard deviation = 10 ; n = sample size = 16

162 + 1.96 (10 /√ 16)

162 + 4.9

( 157.1 , 166.9 )

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.

the second option

step-by-step explanation: