The 1 question is 3 and the second one is 3
For the first question, the answer is A. You take 90 and multiply it by 3, then you get the time that it takes for one worker to mow the large park.
For the second question, you take 50 = k/0.25. To find k, you would want to multiply both sides with 0.25 to cancel the 0.25 on k's side. 50 times 0.25 is 12.5. I think C is your answer although I'm not really confident.
Answer:
The 95% confidence interval for the population mean is between 17.93 days and 24.07 days.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find M as such

In which
is the standard deviation of the population and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 21 - 3.07 = 17.93 days
The upper end of the interval is the sample mean added to M. So it is 21 + 3.07 = 24.07 days
The 95% confidence interval for the population mean is between 17.93 days and 24.07 days.
One gallon per every 16 minute. 8g - 5g = 3g
48 minutes ÷ 3gallons = 16 minute per reduced gallon.