Solve these problems please

The high rate of death, for young children in the past, reduces historical average ages of death. We want a 90% confidence interval for the average age of people buried in Durham city cemeteries from 1910 to 1920 but now we will consider only persons who survived to at least age five. We collect the following sample of ages for that era: 40,69,23,66,78,22,21,31,48,52,23,34 Find the degrees of freedom for this problem: We will use the left edge of the right tail that has area The left edge of this tail is The sample mean is The sample standard deviation is The margin of error is The 90% confidence interval is [ IMPORTANT: This problem is only intended to teach you the procedure for finding a confidence interval for mean. When working this problem, ignore the fact that the sample may be too small and just pretend the procedure for finding a confidence interval works