The sample of 10 healthy children has an average serum ironlevel 19휇mol/l with a standard deviation 6휇mol/l. The sample of6children with cystic fibrosis has an average iron level 12휇mol/lwith a standard deviation of 6.3. An investigator wants to testwhether the mean serum iron levels differ between children with andwithout cystic fibrosis at 95% confidence level(two-sided). Assumethat the serum iron level is approximately normallydistributed.
a)State the null and alternative hypotheses.
b)Calculate the pooled estimate of the variance.
c)Which test statistic do we need to use? t or z? Why?
d)Calculate an appropriate test statistic.
e)Calculate a p-value.
f)Can you reject H0at 95% confidence level?
g)Interpret the result.
