STATS 230 QUIZ 3 Solution Correct Answers 1. How do we calculate the standard error of the mean? a. Sample standard deviation divided by square root of sample size b. Square root of sample variance c. Square root of population variance d. Sample standard deviation divided by sample size Answer: a. Sample standard deviation divided by square root of sample size 2. Which of the following description of the standard error of the mean is correct? a. The standard error of the mean is the standard deviation of the sampling distribution of the mean b. The standard error of the mean is the squared variance of the sampling distribution of the mean c. Standard error is the sample standard deviation d. Standard error is the same with population standard deviation Answer: a. The standard error of the mean is the standard deviation of the sampling distribution of the mean 3. The sample standard deviation is 50, and the sample s ize is 400. What’s the standard error of the mean? (Show work) Answer: 50/ √ 400 = 2.5 4. Which of the following is correct according to the Central limit theorem? a. As the sample size increases, the sample distribution of the mean is closer to the population distribution b. As the sample size increases, the sample distribution of the mean is closer to the normal distribution regardless of whether or not the distribution of the population is normal c. As the sample size increases, the sample distribution of the mean is closer to the normal distribution but only when the distribution of the population is normal d. As the sample size increases, the sample distribution of the mean is closer to the population distribution regardless of whether or not the population distribution is normal Answer: b. As the sample size increases, the sample distribution of the mean is closer to the normal distribution regardless of whether or not the distribution of the population is normal 5. Imagine a high school of 1,000 students. The school administrator wants to know the average height of students in that school. However, he does not know if it makes a difference if he samples more students or less. Thus, your suggestion for him is: a. As you measure more students, the standard error will be smaller b. As you measure more students, the average height will be smaller c. As you measure more students, the variance of sample distribution will be bigger d. As you measure more students, the standard deviation of the sample distribution will be bigger. Answer: a. As you measure more students, the standard error will be smaller 6. The mean of the sampling distribution of the means is___ the mean of the population from which the values were sampled . a. Equal to