A standardized third grade reading test, called the We Can Read Test, has a mean of 50 with a standard deviation of 10. A developmental psychologist conducts a study, where he assesses the reading ability of a random sample of 75 third graders using the We Can Read Test, and finds a mean of 53 with a standard deviation of 12.

Which of the following is a statistic?
a. 50
b. 53
c. 75
d. 10
Which of the following is a parameter?
a. 75
b. 53
c. 10
d. 12

a,c

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A statistic is a measure on a sample, while a parameter is a measure on a population.

To determine which of the options is a statistic and which is a parameter, we need to understand the difference between the two terms.

A statistic is a numerical value that describes a characteristic of a sample. It is calculated using data from the sample and is used to estimate or describe a corresponding population parameter.

A parameter, on the other hand, is a numerical value that describes a characteristic of a population. It is generally unknown and is estimated using statistics calculated from a sample.

Now let's analyze the options:

Which of the following is a statistic?

a. 50: This is the mean of the standardized third grade reading test, but it is not specific to the sample of third graders in the study. Therefore, it is not a statistic.

b. 53: This is the mean of the sample of 75 third graders in the study. It is calculated using data from the sample, so it is a statistic.

c. 75: This represents the sample size, which is the number of third graders in the study. It is not a descriptive value for the sample itself and does not provide any information about a characteristic of the sample. Therefore, it is not a statistic.

d. 10: This is the standard deviation of the standardized third grade reading test, but it is not specific to the sample of third graders in the study. Therefore, it is not a statistic.

Which of the following is a parameter?

a. 75: This represents the sample size, which is not a parameter. Parameters are characteristics of the population, not the sample.

b. 53: This is the mean of the sample of 75 third graders in the study. It is a calculated statistic and not a parameter.

c. 10: This is the standard deviation of the standardized third grade reading test, which is a characteristic of the population. It is estimated using the standard deviation of the sample, so it is a parameter.

d. 12: This is the standard deviation of the sample of 75 third graders in the study. It is a calculated statistic and not a parameter.

In summary, the answer is:
a. The statistic is 53
c. The parameter is 10