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Project 6 Names Q1. A restaurant in an amusement park only offers soft drinks that are Coke products and Pepsi products. People purchasing a soft drink were observed and 178 selected a Pepsi product to drink while 280 selected a Coke product to drink. Utilize this information to find a 95% confidence interval for the proportion of people having a soft drink who select Pepsi product. (Zc=1.96 or Tc=1.98) Q2. A rare congenital disease, Everley's syndrome, generally causes a reduction in concentration of blood sodium. This is thought to provide a useful diagnostic sign as well as a clue to the efficacy а of treatment. Little is known about the subject, but the director of a dermatological department in a London teaching hospital is known to be interested in the disease and has seen more cases than anyone else. Even so, he has seen only 18. The patients were all aged between 20 and 44. The mean blood sodium concentration of these 18 cases was 115 mmol/l, with standard deviation of 12 mmol/l. Assuming that blood sodium concentration is Normally distributed what is the 95% confidence interval within which the mean of the total population of such cases may be expected to lie? (Zc=1.96 or Tc=1.74)
Q3. Construct a 95 % confidence interval an experiment that found the sample mean temperature for a certain city in August was 101.82, with a population standard deviation of 1.2. There were 6 samples in this experiment (Zc=1.96 or Tc=2.015). Q4. A marketing research firm wants to estimate the average amount a student spends during the Spring break. They want to determine it to within $120 with 90% confidence. One can roughly say that the deviation is $400 How many students should they sample? (Use Zc=1.645)