Problem : Too Much Salt? U

Problem : Too Much Salt?

U.S. Food and Drug administration recommends 2400 mg daily allowance of sodium for children. A nutritionist claims that children under the age of 10 years are consuming more sodium than the recommended amount. To test her claim, she obtains a random sample of 110 children under the age of 10 years and measures their daily consumption of sodium. The mean amount of sodium consumed was found to be 2995 mg with a standard deviation of 1489 mg.The distribution of sodium amount is normal. Is this enough evidence to conclude that children under the age 10 consume significantly more sodium than the recommended amount? Use %5 significance level.

1. What type of hypothesis test is needed? What distribution should be used? Why?
2. State the two hypotheses here.
3. Find the critical value and the test statistics. State them here.
4. Is this a right, left or two-tailed test?  Sketch a normal curve, mark the critical value and test statistics and shade the rejection region on the curve.
5. Use your calculator to find the P value. State it here.
6. Do we reject or not reject the null hypothesis?  Is there sufficient evidence to conclude that children under the age of 10 consume significantly more sodium than the recommended amount? What kind of implications can you project for the future health of the children and for the economy based on this study?