A research assistant has conducted a survey of 50 households in a wealthy region the country and

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A research assistant has conducted a survey of 50 households in a wealthy region the country and has given a social scientist 95% and 99% confidence interval for mean household income in the region. The two Intervals (in no particular order) are ($44454, $45546) and ($44584,545416). The research assistant admits that he assumed that the population standard deviation of the household income was known and used a value for the population standard deviation from a previous survey

(a)What is the sample mean of household income in the assistant's survey?

(b)Which of the two intervals is the 95% confidence interval? How do you know this?

(c) The research student was asked to design a new study and told that he needed a margin of error less than $ 500 for a 95% confidence interval how many house holds must he sample for the new study? Use the population standard deviation from the previous survey is 1500. (03).

A recent article that appeared on www.usatoday.com discussed results of a national poll conducted by the Associated Press that asked American parents about their attitudes toward the swine flu vaccine. The article reported based on the sample size of 1000. The finding reported was that 32% surveyed said that they were unlikely to allow their children to be given the swine flu vaccine at school.

(a) Calculate the point estimate (ppp) for the proportion of parents unlikely to allow their children to be given the swine flu vaccine.

(b) Can a valid 95% confidence interval be constructed for p?

(c) Give the 95% confidence interval for p and interpret it. If the National Institute of Health (NIH) wants to do this survey, they decided the margin of- error as is 5% and Use the above information to determine how large a sample do, they need for the survey. Assume that the reported margin-of-error is for a 95% confidence interval (e) If there is no prior information then the sample size needed for the survey is larger or smaller than the one in (e)? (You don't need to calculate)