# Statistics

posted by .

A simple random sample of 50 female 14-year-olds is selected. The sample mean height of the girls is found to be 62 inches. Assume the height of 14-year-old girls is normally distributed with a standard deviation of 5 inches.
1. Based on these data, a 95% confidence interval for the true mean height of all
14-year-old girls is:
A) 62 +/- 1.96
B) 62 +/- 1.386
C) 62 +/- 1.645
D) 62 +/- 0.196
2. Which of the following correctly interprets the 95% confidence interval for the true
mean height of all 14-year-old girls?
A) We can be 95% confident that the sample mean height of 14-year-old girls is within
the confidence interval obtained.
B) If this study were to be repeated with a sample of the same size, there is a 0.95
probability that the sample mean height of 14-year-old girls would be in the interval
obtained.
C) We can be 95% confident that the population mean height of all 14-year-old girls is
within the interval obtained.
D) 95% of all 14-year-old girls have heights within the interval obtained.

• Statistics -

1. 95% = mean ± 1.96SEm

SEm = SD/√n

2. C

• Statistics -

kik

## Similar Questions

1. ### Statistics

The heights of 18-year-old men are approximately normally distributed with mean 68 inches and standard deviation 3 inches. What is the probability that the average height of a sample of ten 18-year-old men will be less than 70 inches?
2. ### Satistics

In North American, female adult heights are approximately normal with a mean of 65 inches and a standard deviation of 3.5 inches. a.) If one female is selected at Random, what is the probablility that shes has a height 70 inches or …
3. ### Statistics

Suppose the mean income of 35-year-olds in the U.S. is \$25,000. A random sample of 150 35-year-olds in California results in a sample mean income of \$26,600 and a sample standard deviation of \$3800. At the 5% significance level, can …
4. ### statistics

The height of 18-year-old men are approximately normally distributed, with mean of 68 inches and a standard deviation of 3 inches. What is the probability that an 18-year-old man selected at random is between 67 and 69 inches tall?
5. ### statistics

Suppose that the heights of female adults in the US are normally distributed with a mean (µ) of 65.4 inches and a standard deviation (σ) of 2.8 inches. Let X denote the height of a randomly chosen adult female. Find the probability …
6. ### statistics

A specific study found that the average number of doctor visits per year for people over 55 is 8 with a standard deviation of 2. Assume that the variable is normally distributed. 1. Identify the population mean. 2. Identify the population …
7. ### statistics

A specific study found that the average number of doctor visits per year for people over 55 is 8 with a standard deviation of 2. Assume that the variable is normally distributed. 1. Identify the population mean. The population mean …
8. ### Statistics

The heights of 18 year old men are approximately normally distributed, with a mean of 67 inches and a standard deviation of 5 inches. What is the probability an 18 year old man selected at random is between 66 and 68 inches?
9. ### Statistics

Suppose the mean income of 35-year-olds in the US is \$25,000. A random sample of 150 35-year-olds in California results in a sample mean income of \$26,600 and a sample standard deviation of \$3800. At the 5% significance level, ca we …
10. ### Statistics

Suppose the heights of 18-year-old men are approximately normally distributed, with mean 66 inches and standard deviation 4 inches. (a) What is the probability that an 18-year-old man selected at random is between 65 and 67 inches …

More Similar Questions