Question

1. 1. Scores on a standardized lesson are assumed to follow a normal distribution, with a mean of 100 and a standard deviation of 32. Five tests are randomly selected. What is the mean test score? (? ) What is the standard error of the scores? ( ?)

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NOTE: The standard error is another name for the standard deviation of , that is, standard error = .

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1. Mean = 100, standard error = 4.53
2. Mean = 100, standard error = 14.31
3. Mean = 100, standard error = 1.43
4. Mean = 100, standard error = 32

2. 2. Scores on a standardized test are assumed to follow a normal distribution, with a mean of 100 and a standard deviation of 32. Fifty tests are randomly selected. What is the mean test score? (? ) What is the standard error of the scores? ( ?)

NOTE: The standard error is another name for the standard deviation of , that is, standard error = .

1. Mean = 100, standard error = 4.53
2. Mean = 100, standard error = 14.31
3. Mean = 100, standard error = 1.43
4. Mean = 100, standard error = 32

3. 3. Scores on a standardized test are assumed to follow a normal distribution, with a mean of 100 and a standard deviation of 32. Five hundred tests are randomly selected. What is the mean test score? (? ) What is the standard error of the scores? ( ?)

NOTE: The standard error is another name for the standard deviation of , that is, standard error = .

1. Mean = 100, standard error = 4.53
2. Mean = 100, standard error = 14.31
3. Mean = 100, standard error = 1.43
4. Mean = 100, standard error = 32

4. Data are collected in a national survey and weighted to reflect the population of all US adults. Suppose that the mean Quality of Life (QOL) score is 70, with a standard deviation of 10. The range of QOL scores is 0-100, with higher scores indicative of better QOL. What is the probability that the mean QOL score in a random sample of 40 adults is 72 or higher?

1. 1.26
2. 0.8962
3. 0.1038
4. -0.8962

5. Total serum cholesterol levels for individuals 65 years of age and older are assumed to follow a normal distribution, with a mean of 182 and a standard deviation of 14.7. If a random sample of 20 individuals aged 65 years or older is selected, what is the probability that their mean total serum cholesterol level is between 180 and 185?

1. 0.2709
2. 0.8186
3. 0.5477
4. 0.0089

6. Total serum cholesterol levels for individuals 65 years of age and older are assumed to follow a normal distribution, with a mean of 170 and a standard deviation of 26.8. If a random sample of 40 individuals aged 65 years or older is selected, what is the probability that their mean total serum cholesterol level is between 180 and 185?

1. 0.2709
2. 0.8186
3. 0.5477
4. 0.0091

Answer 1