Answer:
Randy had 13 books an Sandy had 7 books.
Step-by-step explanation:
20 - 3 = 17
30 - 17 = 13
13 x 2 = 26
26 + 4 = 30
13 + 7 = 20
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Answer:
c is the one with function
Answer:
The best point of estimate for the true mean is:

Since the time can't be negative a good approximation for the confidence interval would be (0,5.248) minutes. The interval are tellling to us that at 95% of confidence the average late time is lower than 5.248 minutes.
Step-by-step explanation:
Information given
represent the sample mean for the late time for a flight
population mean
represent the population deviation
n=76 represent the sample size
Confidence interval
The best point of estimate for the true mean is:

The confidence interval for the true mean is given by:
(1)
The Confidence level given is 0.95 or 95%, th significance would be
and
. If we look in the normal distribution a quantile that accumulates 0.025 of the area on each tail we got
Replacing we got:
Since the time can't be negative a good approximation for the confidence interval would be (0,5.248) minutes. The interval are tellling to us that at 95% of confidence the average late time is lower than 5.248 minutes.