PTC is a substance that has a strong bitter taste for some people and is tasteless for others. The ability to taste PTC is inherited. About76% of people from a certain country can taste PTC, for example. You want to estimate the proportion of people with at least one grandparent from this country who can taste PTC. (Round your answers up to the nearest person.)

(a) Starting with the76% estimate, how large a sample must you collect in order to estimate the proportion of PTC tasters within0.04with 90% confidence?

(b) Estimate the sample size required if you made no assumptions about the value of the proportion who could taste PTC.