In a study of the length of time that students require to earn bachelor's degrees, 100 students are randomly selected and they are found to have a mean of 4.5 years and a standard deviation of 1.8 years. Construct a 90% confidence interval estimate of the population mean.

Select one:

a.(4.31, 4.69)

b.(3.86, 5.14)

c.(4.20, 4.80)

d.None of other answer is necessary true.

e.(4.01, 4.99)

The world's smallest mammal is the bumblebee bat, also known as the Kitti's hog-nosed bat (or Craseonycteris thonglongyai). Such bats are roughly the size of a large bumblebee. A random sample of 16 bumblebee bats has a mean of 1.71 g and a standard deviation of 0.26 g. Assume that bumblebee bats come from the population of which weights are normally distributed. Test the claim that the mean weight of these bats is more than 1.6 g use a 2% significance level. The test statistics and the critical value are

Select one:

a.1.69 and 2.25 respectively

b.2.25 and 1.69 respectively

c.1.69 and 2.60 respectively

d.None of the other answers in necessary true.

e.2.60 and 1.69 respectively

Among 500 randomly selected adults were surveyed, there are 30% of them said that they used the Internet for shopping at least a few times a year. Construct a 95% confidence interval estimate of the percentage of adults who use the Internet for shopping.

Select one:

a.(20.0%, 30.0%)

b.(21.8%, 28.2%)

c.(26.0%, 34.0%)

d.None of the other answers is true.

e.(24.7%, 31.3%)

A pharmaceutical company receives large shipments of tablets and uses this acceptance sampling plan: Randomly select and test 30 tablets, then accept the whole batch if there is only one or none that doesn't meet the required specifications. If a particular shipment of thousands of these tablets actually has a 1% rate of defects, what is the probability that this whole shipment will be accepted?

Select one:

a.77.31%

b.None of other answers is necessary true.

c.73.97%

d.96.39%

e.87.95%

Birth weights in a country are normally distributed with a mean of 3200 g and a standard deviation of 520 g. Find the probability that a randomly selected birth weight is at least 3000g.

Select one:

a.28.20%

b.None of other answers is necessary true.

c.64.97%

d.35.03%

e.71.80%

Among 500 randomly selected adults were surveyed, there are 30% of them said that they used the Internet for shopping at least a few times a year. Construct a 95% confidence interval estimate of the percentage of adults who use the Internet for shopping.

Select one:

a.(20.0%, 30.0%)

b.(21.8%, 28.2%)

c.(26.0%, 34.0%)

d.None of the other answers is true.

e.(24.7%, 31.3%)

1)

The following data shows the height children with time:

Age X, in 18 19 20 21 22 23 24 25 26 27 28 29 (months) Height Y, in 76.1 77.0 78.1 78.2 78.8 79.7 79.9 81.1 81.2 81.8 82.8 83.5 ( cm)