Answer:
Step-by-step explanation:
A) From the stem-leaf plot, we see that out of 21 tunas, 5 have dangerous levels of copper since the levels go beyond 5.7 parts per million. The required proportion is 5/21=0.2381
B) Given the sample mean is {x}=4.77, sample standard deviation s=1.16 and the sample size is n=21.
Since the population standard deviation is not known, we use t-distribution.
So the 98% CI for mean is
4.77 ± t{1-0.02 /2,20} x 1.16/sqrt(21) = (4.13, 5.41)}
We are sure with 98% confidence the true copper level (in parts per million) lies in the interval (4.13, 5.41)
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Answer:
0.8
Step-by-step explanation:
5 is divided by 5 to get to 1. Divide 4 by 5 to get 0.8.
In a ratio, whatever you do to one side you have to do to the others.
