The Food & Drug Administration (FDA) establishes that the "recommended dietary allowance" (RDA) for a vitamin/mineral should be two (2) standard deviations above the mean, which is called the "Estimated Average Requirement" (EAR).  If the RDA of Vitamin C, a.k.a. ascorbic acid, intake is 85 mg (for an adult) and the standard deviation (σ) is 12.5 mg, then find each of the following...

1. What is the EAR (µ) of Vitamin C?

    

    

    

    

    

    

    

    

    

2. What percent of the population consuming (at least) the RDA of Vitamin C would be expected to be meeting their intake needs?

    

    

    

    
   
   

    

    

    

3. Scurvy is a condition which occurs when someone is Vitamin C malnourished.  The FDA considers this level to occur when consumption falls two standard deviations below the mean (EAR).  What level of Vitamin C consumption would potentially put an individual at risk of being afflicted with survy?  What percent of the population could be expected to consume less than this amount and not be so afflicted?

    

    

    

    

    

4. What percent of the population would be expected to need an intake of more than 100 mg of Vitamin C?

    

    

    

    

    

5. In a (random) sample of 1000 individuals, how many would be expected to need an intake of more than 100 mg of Vitamin C?