Question

QUESTION 1:

A 2013 Gallup Poll asked a national random sample of 505 adult women to state their current weight. The mean weight in the sample was x¯¯¯=x¯=158.

We will treat these data as an SRS from a Normally distributed population with standard deviation σ=σ=35.

Give a 95% confidence interval (±±0.01) for the mean weight of adult women based on these data.

The confidence interval is from  to  pounds

QUESTION 2:

Sulfur compounds cause "off-odors" in wine, so winemakers want to know the odor threshold, the lowest concentration of a compound that the human nose can detect. The odor threshold for dimethyl sulfide (DMS) in trained wine tasters is about 25 micrograms per liter of wine (μμg/ l). The untrained noses of consumers may be less sensitive, however.

You want to estimate the mean DMS odor threshold among all students, and you would be satisfied to estimate the mean to within ±±0.2 with 95 % confidence.

The standard deviation of the odor threshold for untrained noses is known to be σσ = 7 micrograms per liter of wine.

How large an SRS of untrained students do you need?

Answer 1

Q1)