Suppose that the annual interest rates on mortgages in the U. S. are normally distributed with an unknown mean and standard deviation. The rates of 22 randomly sampled mortgages (home loans) are used to estimate the mean of the population. What t-score should be used to find the 98% confidence interval for the population mean?

The value is

Step-by-step explanation:

From the question we are told that

   The  sample size is  n =  22

Generally the degree of freedom is mathematically represented as

=>    

=>    

From the question we are told the confidence level is  98% , hence the level of significance is    

=>  

Generally from the t distribution table the critical value  of    at a degree of freedom of  is  

$30.32

step-by-step explanation:

65.00*.12=2.80

65.00-2.80=57.20

57.20*1.06=60.632

60.632/2=30.316

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.