Problem-3 Students of a large university spend an average of $5 a day on lunch. The standard deviation of the expenditure is $3. A simple random sample of 36 students is taken. a) What are the expected value, standard error, and shape of the sampling distribution of the sample mean? b) What is the probability that the sample mean will be at least $4? c} What is the probability that the sample mean will be at most $5.50? Problem-4 A new soft drink is being market tested. It is estimated that 60% of consumers will like the new drink. A sample of 96 tasters tested the new drink. a) Determine the standard error of the proportion b) What is the probability that more than ?5% of consumers will indicate they like the drink? c) What is the probability that more than 30% of consumers will indicate they do not like the drink? Chagter-B Problems: Problem-5 To estimate the average electric usage per month, a sample of 196 houses was selected, and their electric usage was determined. Assume a population standard deviation of 350- kilowatt hours. a} Determine the standard error of the mean. b} With a 0.95 probability, determine the margin of error. c} If the sample mean is 2,000 KWH, what is the 95% condence interval estimate of the population mean? Problem-8 An Excel printout of the descriptive measures of daily checking account balances (in dollars) of customers of First Daisy Bank is shown below. Develop a 95% condence interval estimate for the mean of the population of the checking balances. Account Balance Information Mean 4828.28 Median 5115.25 Mode 40?6.50 Sample Standard Deviation 1143.5? Sample 'v'ariance 130??63.49 Kurtosis 8.63 Skewness -3.06 h.) Range 4968.50 Minimum 600.00 Maximum 5568.50 Sum 173818.50 Count 36.00 Problem-? In a random sample of 400 residents of Boston, 320 residents indicated that they voted for Obama in the last presidential election. Develop a 05% confidence interval estimate for the proportion of all Boston residents who voted for Dbama