in a small country, the mean cost of hospitalization for asthma for an adult is 2,500 euros (standard deviation: 1,800 euros). The mean cost in a sample of 45 is 3,000 euros. test the hypothesis that the mean cost in the sample is representative of the mean cost in the population. (alpha = 0.05)

1. state the null and alternative hypotheses

2. calculate the standard error

3. calculate the z score and perform the hypothesis test

calculate the 95% confidence interval for the sample mean