1 1 pts A simple random sample of 28 observations was taken from a large population. The sample mean equaled 50. Fifty is a _____. Group of answer choices point estimator population parameter point estimate sample parameter Flag question: Question 2 Question 2 1 pts Random samples of size 81 are taken from an infinite population whose mean and standard deviation are 200 and 18, respectively. The distribution of the population is unknown. The mean and the standard error of the distribution of sample means are _____. Group of answer choices 200 and 2 81 and 18 9 and 2 200 and 18 Flag question: Question 3 Question 3 1 pts The fact that the sampling distribution of the sample mean can be approximated by a normal probability distribution whenever the sample size is large is based on the _____. Group of answer choices fact that there are tables of areas for the normal distribution assumption that the population has a normal distribution central limit theorem normal probability theorem Flag question: Question 4 Question 4 1 pts A population has a mean of 180 and a standard deviation of 24. A sample of 64 observations will be taken. The probability that the mean from that sample will be between 183 and 186 is _____. Group of answer choices 0.8185 0.4772 0.1359 0.3413 Flag question: Question 5 Question 5 1 pts Exhibit 7-1 The following data were collected from a simple random sample from an infinite population. 13 15 14 16 12 Refer to Exhibit 7-1. The point estimate of the population mean _____. Group of answer choices cannot be determined because the population is infinite is 14 is 5 is 4 Flag question: Question 6 Question 6 1 pts A random sample of 25 employees of a local company has been measured. A 95% confidence interval estimate for the mean systolic blood pressure for all company employees is 123 to 139. Which of the following statements is valid? Group of answer choices If the sampling procedure were repeated many times, 95% of the resulting confidence intervals would contain the population mean systolic blood pressure. If the sampling procedure were repeated many times, 95% of the sample means would be between 123 and 139. 95% of the sample of employees has a systolic blood pressure between 123 and 139. 95% of the population of employees has a systolic blood pressure between 123 and 139. Flag question: Question 7 Question 7 1 pts We can reduce the margin of error in an interval estimate of p by doing any of the following EXCEPT _____. Group of answer choices using a planning value p* closer to .5 increasing the level of significance reducing the confidence coefficient increasing the sample size Flag question: Question 8 Question 8 1 pts The expression used to compute an interval estimate of may depend on any of the following factors EXCEPT _____. Group of answer choices whether the population has an approximately normal distribution the sample size whether the population standard deviation is known whether there is sampling error Flag question: Question 9 Question 9 1 pts An interval estimate is used to estimate _____. Group of answer choices the shape of the population's distribution the sampling distribution a sample statistic a population parameter Flag question: Question 10 Question 10 1 pts As the sample size increases, the margin of error _____. Group of answer choices becomes negative increases stays the same decreases Flag question: Question 11 Question 11 1 pts The z value for a 97.8% confidence interval estimation is _____. Group of answer choices 1.96 2.02 2.00 2.29 Flag question: Question 12 Question 12 1 pts The practice of concluding "do not reject H0" is preferred over "accept H0" when we _____. Group of answer choices are testing the validity of a claim have not controlled for the Type II error are conducting a one-tailed test have an insufficient sample size Flag question: Question 13 Question 13 1 pts Which of the following is an improper form of the null and alternative hypotheses? Group of answer choices and and and and Flag question: Question 14 Question 14 1 pts Your investment executive claims that the average yearly rate of return on the stocks she recommends is at least 10.0%. You plan on taking a sample to test her claim. The correct set of hypotheses is _____. Group of answer choices H0: 10.0% Ha: < 10.0% H0: < 10.0% Ha: 10.0% H0: > 10.0% Ha: 10.0% H0: 10.0% Ha: > 10.0% Flag question: Question 15 Question 15 1 pts A student believes that the average grade on the final examination in statistics is at least 85. She plans on taking a sample to test her belief. The correct set of hypotheses is _____. Group of answer choices H0: 85 Ha: < 85 H0: < 85 Ha: 85 H0: > 85 Ha: 85 H0: 85 Ha: > 85 Flag question: Question 16 Question 16 1 pts The manager of an automobile dealership is considering a new bonus plan in order to increase sales. Currently, the mean sales rate per salesperson is five automobiles per month. The correct set of hypotheses for testing the effect of the bonus plan is _____. Group of answer choices H0: 5 Ha: > 5 H0: < 5 Ha: 5 H0: 5 Ha: < 5 H0: > 5 Ha: 5 Flag question: Question 17 Question 17 1 pts In hypothesis testing, if the null hypothesis has been rejected when the alternative hypothesis has been true, _____. Group of answer choices a Type II error has been committed the correct decision has been made the sample size is too small a Type I error has been committed Flag question: Question 18 Question 18 1 pts A two-tailed test at a .0694 level of significance has z values of _____. Group of answer choices -1.09 and 1.09 -1.96 and 1.96 -1.48 and 1.48 -.86 and .86 Flag question: Question 19 Question 19 1 pts A one-tailed test (upper tail) at a .123 level of significance has a z value of _____. Group of answer choices 1.16 1.96 1.54 1.645 20.) A two-tailed test is performed at a 5% level of significance. The p-value is determined to be .09. The null hypothesis _____. Group of answer choices has been designed incorrectly should not be rejected may or may not be rejected, depending on the sample size must be rejected