Use rigid motion to write a proof of the converse of isosceles triangle theorem

The 99% confidence interval for the mean number of toys purchased each year is between 7.6 toys and 7.8 toys.

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 7.7 - 0.1 = 7.6 toys

The upper end of the interval is the sample mean added to M. So it is 7.7 + 0.1 = 7.8 toys

The 99% confidence interval for the mean number of toys purchased each year is between 7.6 toys and 7.8 toys.