Each year, all final year students take a mathematics exam. It is hypothesized that the population mean score for this test is 85. It is known that the population standard deviation of test scores is 11. A random sample of 30 students take the exam. The mean score for this group is 100.
Calculate the 95% confidence interval for the population mean test score. Give your answers to 2 decimal places.

Ihave trouble finding the nth term of a linear sequence

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.

The birth weights of newborn babies in the unites states follow in a normal distrubution with a mean of 3.4 kg and standard deviation of 0.6 kg. reaserches interested in studying how. children gain weights decide to take random samples of 100 newborn babies and calculate the sample mean birth weights for each sample