The lifetime (in hours) of a 60-watt light bulb is a random variable that has a Normal distribution with standard deviation 30. A random sample of 25 bulbs put on test produced a sample mean lifetime of 1038. The 92% confidence interval estimate for the mean lifetime, μ, is (1027.5, 1048.5). If it were desired to cut the confidence interval to half its length while keeping the same 92% level, what size sample would be required to achieve this?

The annual snowfall in a town has a mean of 38 inches and a standard deviation of 10 inches. last year there were 63 inches of snow. find the number of standard deviations from the mean that is, rounded to two decimal places. 0.44 standard deviations below the mean 2.50 standard deviations below the mean 0.44 standard deviations above the mean 2.50 standard deviations above the mean

What is the absolute value of the complex number -4-sqrt2i

Questions 7-8. use the following table to answer. year 2006 2007 2008 2009 2010 2011 2012 2013 cpi 201.6 207.342 215.303 214.537 218.056 224.939 229.594 232.957 7. suppose you bought a house in 2006 for $120,000. use the table above to calculate the 2013 value adjusted for inflation. (round to the nearest whole number) 8. suppose you bought a house in 2013 for $90,000. use the table above to calculate the 2006 value adjusted for inflation. (round to the nearest whole number)