Delroy McWilliams, a quantitative analyst with Churn Brothers Brokerage, is examining a data sample and has amassed the following information:
Standard deviation of the sample: 70
Number of observations: 600 -
Sample mean: 812 -
Assume that Mr. McWilliams formulates a null hypothesis that states that the value of the population mean is equal to 800. Additionally, assume that the population standard deviation is unknown. Given this information, what is the standard error of the estimate? Further, what is the test statistic? Choose the best answer.
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A. B. C. D. E. F. G.C
The standard error and test statistic for this example is 2.858 and 4.199, respectively. Therefore, none of these answers is correct.
If the population standard deviation is unknown, as in this example, the standard error of the estimate is found by using the following equation:
{Standard error = s / square root of n} where s = the sample standard deviation and n = the number of observations in the sample.
In this example, all of the necessary information has been provided, and the determination of the standard error of the estimate is found as:
{Standard error = [70 / 24.495] = 2.858}
Now that the standard error of the estimate has been calculated, the test statistic can be found by using the following equation:
{Test statistic = [sample statistic - value of the population parameter under the null hypothesis] / standard error of the sample statistic].
Again, all of the necessary information has been provided, and the calculation of the test statistic is found as follows:
{Test statistic = [812 - 800] / 2.858 = 4.199}