Answer:
So the answer for this case would be n=183 rounded up to the nearest integer
Step-by-step explanation:
Information provided
represent the sample mean
population mean (variable of interest)
represent the population standard deviation
n represent the sample size
the margin of error desired
Solution to the problem
The margin of error is given by this formula:
(a)
And on this case we have that ME =0.023 and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
The confidence level is 97% or 0.97 and the significance would be
and
then the critical value would be:
, replacing into formula (5) we got:
So the answer for this case would be n=183 rounded up to the nearest integer
It is suppose to be letter d
2hrs and 18 mins = 138 mins
381 km / 138 mims = 2.76 km / minute
2.76 km / min * 60 = 165.6 km / hr
His two speeds for the whole journey include 165.6 km / hr and 30 km / hr.
165.6 + 30 = 195.6
195.6 / 2 = 97.8 km / hr
The average speed is 97.8 km / hr