In: Statistics and Probability
The sample of 10 healthy children has an average serum iron level 19휇mol/l with a standard deviation 6휇mol/l. The sample of 6children with cystic fibrosis has an average iron level 12휇mol/l with a standard deviation of 6.3. An investigator wants to test whether the mean serum iron levels differ between children with and without cystic fibrosis at 95% confidence level(two-sided). Assume that the serum iron level is approximately normally distributed.
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.