confidence intervals for a proportion

A survey of 120 families showed that at least 78 had a computer at home. Find the 99% confidence interval of the true proportion of families who own a home computer. => 64.5% < p < 65.5% or 5.38% < p < 7.62% or 53.8% < p < 76.2% or 60.6% < p < 6..

An investigation was done to examine the proportion of male teenagers who smoke. From a pilot study, it was found that out of 150 males, 40 smoked. Find the 99% confidence interval of the true proportion of teenagers who smoke. => 16.05% < p < 37.95% or..

A survey of 156 people showed that 104 go for a brisk walk daily. Find the 99% confidence interval of the true proportion of people who go for a brisk walk. => 57.3% < p < 76.7% or 63.2% < p < 70.8% or 66.6% < p < 67.4% or 66% < p < 70%..

A recent study of 160 people of a locality in a city found that 39 people were obese. Find the 95% confidence interval of the population proportion of individuals living in that city who are obese. => 17.7% < p < 31.1% or 17% < p < 31% or 21% < p < 27..

A survey of 90 recent fatal traffic accidents showed that 52 were alcohol-related. Find the 90% confidence interval of the true proportion of alcohol-related accidents. => 49.4% < p < 66.6% or 50% < p < 66% or 0.49% < p < 0.66% or 52.8% < p < 63..

In a survey of 500 canned fish, 150 fish has a potassium content of 3800 ppm. Find the 95% confidence interval for the true proportion of canned fish whose potassium content is 3,800 ppm. => 22.7% < p < 37.3% or 26% < p < 34% or 26.3% < p < 33.7% or 6..

A food technologist wishes to estimate the effects of chicken's diet on the cholestrol content of the yolks of the resulting eggs. She has selected a random of 350 eggs from chickens, which were given the standard diet and found that the cholestrol content in the yolks of 280 eggs to be 10.53 mg/g ..

A recent study of 50 people in a city found that 70% of the people have less than average incomes for the city. How many people should be surveyed to estimate the true proportion of people having an income of less than average with a 99% confidence interval 4% wide? =>..

Based on a sample of 150 students at a university, it was found that 112 of those students walk or use bike to travel to university. Construct a 95% confidence interval for p , the proportion of all students who use bike or walk to school. => 71.5% < p < 78.5% or..

The formula for the confidence interval for a standard deviation is ________ . => III or II or IV or I..