Given:
n = 20, sample size
xbar = 17.5, sample mean
s = 3.8, sample standard deiation
99% confidence interval
The degrees of freedom is
df = n-1 = 19
We do not know the population standard deviation, so we should determine t* that corresponds to df = 19.
From a one-tailed distribution, 99% CI means using a p-value of 0.005.
Obtain
t* = 2.8609.
The 99% confidence interval is
xbar +/- t*(s/√n)
t*(s/√n) = 2.8609*(3.8/√20) = 2.4309
The 99% confidence interval is
(17.5 - 2.4309, 17.5 + 2.4309) = (15.069, 19.931)
Answer: The 99% confidence interval is (15.07, 19.93)

now, the circle of the clock has 360°, if we divide it by 60(minutes), we get 360/60, just 6° for each minute.
now, if there are 6° in 1 minute, how many minutes in 95.49°?
well, just 95.49/6 or about 15.92 minutes, I take it you can round it up to 16 minutes.
so 16 minutes since noon, so is about 12:16, about time get the silverware for lunch.
1. 0 - 34 + 13 - 5 = -26.....26 ft below the surface
2. y = 15x + 50
220 = 15x + 50
220 - 50 = 15x
170 = 15x
170/15 = x
11 1/3 = x......he worked 11 1/3 hrs.......not sure about this...because it does not specify how many visits he made...but if this was just for 1 visit, then he worked 11 1/3 hrs