Question

6 With a sample size of 177, a 95% confidence interval for the height of 9-year old male US children is (54.0, 54.8), Indicate which of the following is a true statement A. All samples of size 177 of the population of 9-year old male US children will generate confidence intervals of (54.0, 54.8). B. The probability is 0.05 that a randomly selected 9-year old male US child will be more than 54.8 inches. C. If the process of selecting a sample of size 177 is repeated, 95% of the confidence intervals created will contain the true average height of 9-year old male US children. C D. None of the above A 7 The mean birth weight in 2014 of a random sample of 81 full term newborns HA selected at random in a U.S. city is found to be 7.4 lb., with a standard deviation of HA 1.3 lb. A researcher wanted to estimate the mean birth weight, u, of all full term newborns in 2014 in the U.S. city. Assuming that the standard deviation of weights for all full term newborns in the U.S. city in 2014 is 1.3, which of the following is the I h standard error that would be used in creating the 95% confidence interval for u? e ri on CA 1.3/81 B. 1.96x (1.3//81) evi C c. 1.3//81 1.96/V81 CE. 7.4+ 1.96x (1.3//81) sco D othe not les than

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Answer 1

7.)

standard error
(used in confidence interval)= $\frac{\sigma }{\sqrt{n}}\\ =\frac{1.3}{\sqrt{81}}\\$

therefore option D