The formula for the confidence interval is given by
Sample mean + z*[σ/√n], and
Sample mean - z*[σ/√n]
We have:
Sample mean = 23.95
n = 40
σ = 2.55
z* for 99% confidence = 2.58
Substitute these values into the formula, we have
23.95 + (2.58)(2.55÷√40) = 24.99
23.95 - (2.58)(2.55÷√40) = 22.91
So the lower interval is 22.91 and the highest interval is 24.99
They’re similar bc all sides have the same scale factor
Answer: $130.50
Step-by-step explanation:
2.5 hours= $25 an hour
25+25+12.50=$62.50
Muffler=$65
65plus62.50
Total= $130.50
Answer:
15 miles
Step-by-step explanation:
the 2 mph is a red herring. If there is a rate of 10 mph, and the trip took 1.5 hours, the 1 hour=10 miles, and the .5=5 miles, add em up and its 15 miles
36 donuts (2 1/2 dozen) = $8.00
So, you divide 8 by 36 and you get about 22¢ for each donut. Then, you do .22 x 12 which equals $2.64.
One dozen donuts = $2.64
