QMB 3200 Chapter 7-17 Final Exam Test Prep Questions And Answers 100% Verified

QMB 3200 Chapter 7-17 Final Exam Test Prep Questions And Answers 100% Verified A simple random sample of 64 observations was taken from a large population. The sample mean and standard deviation were determined to be 320 and 120, respectively. The standard error of the mean is: - answer15. Which of the following is a point estimator? - answers How many simple random samples of size 5 can be selected from a population of size 8? - answer56 Doubling the size of the sample will: - answerreduce the standard error of the mean. In a recent Gallup Poll, the decision was made to increase the size of its random sample of voters from 1500 people to about 4000 people. The purpose of this increase is to: - answerreduce the standard error of the estimate. The probability distribution of all possible values of the sample proportion p is the: - answersampling distribution of p. The standard deviation of a point estimator is called the: - answerstandard error. The value of the _____ is used to estimate the value of the population parameter. - answersample statistic Which of the following statements regarding the sampling distribution of sample means is incorrect? - answerThe standard deviation of the sampling distribution is the standard deviation of the population. The sampling distribution of p is the: - answerprobability distribution of all possible values of the sample proportion. A sample of 400 observations will be taken from an infinite population. The population proportion equals .8. The probability that the sample proportion will be greater than .83 is: - answer.0668. The medical director of a company looks at the medical records of all 50 employees and finds that the mean systolic blood pressure for these employees is 126.07. The value of 126.07 is: - answera parameter A simple random sample of 100 observations was taken from a large population. The sample mean and the standard deviation were determined to be 80 and 12, respectively. The standard error of the mean is: - answer1.20 The distribution of values taken by a statistic in all possible samples of the same size from the same population is called a: - answersampling distribution. For a(n) _____ , it is impossible to construct a sampling frame. - answerinfinite population Which of the following is a nonprobability sampling technique? - answerJudgment sampling The fact that the sampling distribution of sample means can be approximated by a normal probability distribution whenever the sample size becomes large is based on the: - answercentral limit theorem. A simple random sample of size n from a finite population of size N is a sample selected such that each possible sample of size: - answern has the same probability of being selected. Random samples of size 100 are taken from an infinite population whose population proportion is .2. The mean and standard deviation of the sample proportion are: - answer.2 and .04. A random sample of 12 four-year-old red pine trees was selected and the diameter (in inches) of each tree's main stem was measured. The resulting observations are as follows: 11.3, 10.7, 12.4, 15.2, 10.1, 12.1, 16.2, 10.5, 11.4, 11.0, 10.7, and 12.0 Find the point estimate that can be used to estimate the true population mean. - answerx = 11.97 A probability sampling method in which we randomly select one of the first k elements and then select every kth element thereafter is: - answersystematic sampling. Sample statistics, such as x, s, or p, that provide the point estimate of the population parameter are known as: - answerpoint estimators. A random sample of 150 people was taken from a very large population. Ninety of the people in the sample were female. The standard error of the proportion is: - answer.0400. A simple random sample of size n from an infinite population of size N is to be selected. Each possible sample should have: - answerthe same probability of being selected. Which of the following is(are) true? I. The mean of a population depends on the particular sample chosen. II. The standard deviations of two different samples from the same population may be the same. III. Statistical inferences can be used to draw conclusions about the populations based on sample data. - answerII and III The population we want to make inferences about is called the: - answertarget population When drawing a sample from a population, the goal is for the sample to: - answermatch the targeted population. A simple random sample of size n from an infinite population is a sample selected such that: - answereach element is selected independently and is selected from the same population. A doctor would like to determine if there is a difference between the blood pressure of people who walk every day for 60 minutes and those who walk one day per week for 60 minutes. Fifty of her patients who report that they have routinely walked 60 minutes every day for the past two years and 50 who report that they have walked 60 minutes only one day per week will be identified. The doctor will examine their medical records and collect their blood pressure readings over this two-year period. This is an example of a(n): - answerobservational study. Which of these best describes a sampling distribution of a statistic? - answerIt is the distribution of all of the statistics calculated from all possible samples of the same sample size. In a survey of public opinion concerning state aid to a particular city, every 40th person registered as a voter was interviewed, beginning with a person selected at random from among the first 40 listed. This is an example of: - answersystematic sampling. The central limit theorem states that: - answerif the sample size n is large, then the sampling distribution of the sample mean can be approximated by a normal distribution. The central limit theorem is important in Statistics because it: - answerenables reasonably accurate probabilities to be determined for events involving the sample average when the sample size is large regardless of the distribution of the variable. As a rule of thumb, the sampling distribution of the sample proportion can be approximated by a normal probability distribution when: - answern(1 - p) ≥ 5 and np≥ 5. Convenience sampling is a: - answernonprobability sampling technique. We wish to draw a sample of size 5 without replacement from a population of 50 households. Suppose the households were numbered 01 to 50. Using the following line from a random number table, the households selected would be: 1 1 3 6 2 3 5 6 9 2 9 6 2 3 7 9 0 8 4 2 4 6 8 4 3 6 2 7 1 9 6 4 0 4 - answer11, 36, 23, 56, and 92 Which of the following is not a symbol for a parameter? - answers Cluster sampling is: - answera probability sampling method. Parameters are: - answernumerical characteristics of a population. A sample of 92 observations is taken from an infinite population. The sampling distribution of x is approximately: - answernormal because of the central limit theorem. There are 6 children in a family. The number of children defines a population. The number of simple random samples of size 2 (without replacement) that are possible is equal to: - answer15. As the sample size increases, the: - answerstandard error of the mean decreases. A sample of 66 observations will be taken from an infinite population. The population proportion equals .12. The probability that the sample proportion will be less than .1768 is: - answer.92 In computing the standard error of the mean, the finite population correction factor is used when: - answern/N>.05 The distribution of values taken by a statistic in all possible samples of the same size from the same population is the sampling distribution of: - answerthe sample. The sample statistic characteristic s is the point estimator of: - answero The sample mean is the point estimator of: - answeru In stratified random sampling: - answerrandomly selected elements within each of the strata form the sample. A random sample of 121 bottles of cologne showed an average content of 4 ounces. It is known that the standard deviation of the contents (i.e., of the population) is .22 ounces. In this problem, the value .22 ounces is: - answera parameter As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution: - answerbecomes smaller A random sample of 144 observations has a mean of 20, a median of 21, and a mode of 22. The population standard deviation is known and is equal to 4.8. The 95.44% confidence interval for the population mean is: - answer19.200 to 20.800 1-.9544=.0228 1-.0228=.9772 Look for 0.9772 z value, which is 2.00 mean+- sigma/sqrt(sample size) 20+- 4.8/sqrt(144) 20+- 4.8/12 = 20+- 0.8 19.2 to 20.8 The manager of a grocery store has taken a random sample of 100 customers. The average length of time it took these 100 customers to check out was 3.0 minutes. It is known that the standard deviation of the population of checkout times is one minute. The standard error of the mean is equal to: - answer0.1 sigma/sqrt(n) 1/sqrt(100) = 1/10 = 0.1 An approximate value of a population parameter that provides limits and believed to contain the value of the parameter is known as the: - answerinterval estimate An elementary school teacher asked a random sample of 12 of her students what their favorite number was. Assume the population of responses would follow a normal distribution. The students stated that their favorite numbers are: 2 10 7 4 0 5 6 4 4 6 1 100 What is the appropriate degrees of freedom to use when calculating a 95% confidence interval for μ ? - answer11