Q1) Survey of 85 families illustrated that 36 owned at least one DVD player.  Determine the 99% confidence interval estimate of true proportion of families who own at least on DVD player. 

2) Manufacturer of flashlight batteries took sample of 13 batteries from day's production and used them continuously until they failed to work.  Life lengths of batteries, in hours, until they failed were:  342, 426, 317, 545, 264, 451, 1049, 631, 512, 266, 492, 562, and 298. 

At.05 level of significance, is there evidence to propose that mean life length of batteries produced by this manufacturer is more than 400 hours?  

a) No, as p-value for this test is equal to .1164

b) Yes, as test value 1.257 is less than the critical value 1.782

c) No, as test value 1.257 is greater than the critical value 1.115

d) Yes, as test value 1.257 is less than the critical value 2.179