Answer:
multiplication
Step-by-step explanation:
Answer:
With 95% confidence when n equals 44, the population mean is between a lower limit of 33.96 and an upper limit of 40.04
Step-by-step explanation:
Confidence Interval = mean + or - Error margin (E)
mean = 37
sd = 10
n = 44
degree of freedom = n - 1 = 44 - 1 = 43
t-value corresponding to 43 degrees of freedom and 95% confidence level is 2.0165
E = t × sd/√n = 2.0165×10/√44 = 3.04
Lower limit = mean - E = 37 - 3.04 = 33.96
Upper limit = mean + E = 37 + 3.04 = 40.04
95% confidence interval is between 33.96 and 40.04
Before the mechanic worked on it, it cost .09 (cents) per mile. After the mechanic worked on it, it cost .08 (cents) per mile. Divide the number of gallons by the miles in each case and multiply the result by 4.
5x = 20...where x = number of months
x = 20/5
x = 4...it would take Tom 4 months to save $20
