Complete the square to rewrite y= x^2 + 6x + 3 in vertex form

The number of hours per week that the television is turned on is determined for each family in a sample. the mean of the data is 37 hours and the median is 33.2 hours. twenty-four of the families in the sample turned on the television for 22 hours or less for the week. the 13th percentile of the data is 22 hours. approximately how many families are in the sample? round your answer to the nearest integer.

For how answer my question this will be the last question can you answer in math subject

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.