A random sample of 25 families leaving a supermarket yields an average grocery bill of $112.36, with a standard deviation of $32.45. A histogram of the data is approximately normal. Construct a 95% confidence interval for the average grocery bill of all households whose members shop at this store.
Answer to relevant QuestionsA random sample of monthly daycare costs for 50 households in Halifax, Nova Scotia, yields an average of $460, with a standard deviation of $65. Estimate the average monthly daycare costs for all Halifax households, with 98% ...A restaurant is trying to decide how to target its marketing. The owner thinks that diners on business expense accounts typically spend more on food and wine than do other diners. The restaurant takes a random sample of 40 ...How large a sample size should the manufacturer described in Exercise 18 take if it wants to estimate annual maintenance costs for this entry-level compact in the third year of its life to within $10, with 98% confidence? A poll taken for Toronto Life magazine in the fall of 2005 surveyed 316 adults in the greater Toronto area. Four in 10 said they would keep their jobs even if they won $10 million in the lottery. Provide a 90% confidence ...A random sample of 250 attendees of a wine and cheese festival were asked to rate Californian and French wines. Of the 250, 25 rated the wines about equal. Of the remainder, 150 rated Californian wines higher than French ...
Post your question