Ameasurement of fluoride ion in tooth paste from 5 replicate measurements delivers a mean of 0.14 % and a standard deviation of 0.05 %. what is the confidence interval at 95 % for which we assume that it contains the true value?

The confidence interval at 95 % for which we assume that it contains the true value is (0.0962, 0.1838).

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 mean subtracted by M. So it is 0.14 - 0.0438 = 0.0962

The upper end of the interval is the mean added to M. So it is 0.14 + 0.0438 = 0.1838

The confidence interval at 95 % for which we assume that it contains the true value is (0.0962, 0.1838).

126.66 m²

step-by-step explanation:

the pertinent area formula is a = πr², where r is the radius.

here, a = π(6.35 m)² = 40.32π, or approximately 126.66 m²

at least two

step-by-step explanation: