Need Help On Random Samples PLeaseeee?

According to the national restaurant association, 20% of fine-dining restaurants have instituted policies restricting the use of cell phones. If you select a random sample of 100 fine-dining restaurants





a)What is the probability that the sample has between 15% and 25% that have established policies restricting cell phone use?


b)The probability is 90% that the sample percentage will be contained within what symmetrical limits of the population percentage?


c)The probability is 95% that the sample percentage will be contained within what summetrical limits of the population percentage








If someone can explain this to me since i havent been in class i injured my leg during a football game and couldnt walk please help me

Need Help On Random Samples PLeaseeee?
Were the samples the NRA took random? How did they define "fine-dining?" OK First, 1/5 of the restaurants had the policy. If it was random, and if you select the same type of restaurant as defined by their parameters, and if they didn't massage the numbers too much, the chances are 100% that 20 of your 100 will have the same type of policy. The easiest way to check, is to do your own survey, or do a null-hypothesis. Check your book for Pierson or Fisher formulae for checking results. Wish I could help more, but it's been almost 15 years, and I barely made it in stats. You could always call your prof. or the study skills center at your school.