122) The average battery life of the iPhone 4S is reported to be 6.0 hours by Apple. Assume that the standard deviation for the battery life for this cell phone is 30 minutes. A random sample of 50 iPhones had an average battery life of 5.7 hours. Use a 90%.
21) One method to reduce nonsampling errors is to increase the size of the sample.
22) A common source of nonsampling errors is a survey that contains ambiguous questions in the eyes of the respondent.
23) To use the Central Limit Theorem, we need to know the mean and standard deviation of.
85) The MBA program at Dover College has an enrollment of 160 students with an average age of 34.7 years old and a standard deviation 5.2 years. A random sample of 40 MBA students was selected. What is the probability that the average age of the sample is less than.
110) Breyers is a major producer of ice cream and would like to test the hypothesis that the average American consumes more than 17 ounces if ice cream per month. A random sample of 15 Americans was found to consume an average of 18.2 ounces of ice cream last month..
65) For a sample size of two or more, the standard error of the mean must be
A) equal to the population standard deviation.
B) less than the population standard deviation.
C) less than the population mean.
D) more than the population mean.
66) As the size of the sample increases,
A) the standard error of.
105) In 2010, FHA mortgages, which are insured by the federal government, accounted for 33% of all home-purchase mortgages that were approved. A random sample of 160 mortgage applications from 2010 was selected. What is the probability that 56 or more from this sample were insured by the FHA?
A) 0.1335
B).
135) A recent survey found that 42% of IT professionals monitor employees trying to access video stream of the NCAA Men's Basketball Tournament. A random sample of 75 IT professionals was selected. What is the probability that between 40% and 48% of this sample will monitor employees trying to access.
96) The Retail Advertising and Marketing Association would like to estimate the average amount of money that a person spends for Mother's Day with a 99% confidence interval and a margin of error within plus or minus $6. Assuming the standard deviation for spending on Mother's Day is $36, the.
45) Susan would like to conduct a survey of homeowners in the Meadowbrook neighborhood to get their opinions on proposed road modifications in the area. Which of the following is an example of a convenience sample?
A) Susan randomly chooses two streets in the neighborhood and selects every home on these.
62) According to Pew Research Center, 71% of Internet users accessed video-sharing sites in August 2011. A random sample of 50 Internet users was selected. Using the normal approximation to the binomial distribution, what is the probability that 37 or more people from this sample access video-sharing sites?
A) 0.1492
B) 0.2676
C).
90) The Department of Transportation would like to test the hypothesis that the average age of cars on the road is less than 10 years. A random sample of 50 cars had an average age of 9.5 years. It is believed that the population standard deviation for the age of.
95) According to IDC, Apple's share of the smartphone market was 20% during the 3rd quarter of 2011. A random sample of 115 smartphone users was selected. The standard error of the proportion is ________.
A) 0.0157
B) 0.0373
C) 0.0690
D) 0.1016
96) The No Child Left behind Act of 2001 (NCLB) established standards-based.
21) The degrees of freedom are the number of values that are free to vary given that certain information, such as the sample mean, is known.
22) The degrees of freedom are used to determine the critical z-score for the normal distribution when calculating a confidence interval.
23) When we use the.
1) Measuring the entire population is usually preferred over measuring a sample from the population.
2) Sampling without replacement means that once a member of a population is chosen for a sample, it cannot be chosen again for the same sample.
3) Excel's random sampling tool uses sampling with replacement.
4) With systematic.
56) A survey by American Express Spending reported that the average amount spent on a wedding gift for a close family member is $166. A random sample of 45 people who purchased wedding gifts for a close family member spent an average of $160.50. Assume that the population standard deviation.
127) The average grocery bill at the cash register for a random sample of 10 shoppers at a local store is $53.80 with a sample standard deviation of $18.40. Determine the margin of error for a 90% confidence interval for this sample.
128) The average grocery bill at the cash register.
155) The pH scale measures the amount of alkalinity or acidity in a liquid and ranges from 0 to 14. The ideal pH for a swimming pool is 7.2. A pH that is too high or low can cause discomfort for the swimmers, especially in the eyes. Chemicals need to.
132) Frito-Lay fills bags of tortilla chips that are labeled with a net weight of 288.5 grams. A random sample of 24 bags is selected and found to have an average net weight of 289.7 grams and a sample standard deviation of 5.6 grams. Use a 95% confidence interval to.
11) A convenience sample is an example of a nonprobability sample.
12) An Internet poll, where individuals may respond to a survey as many times as they choose to, is an example of a nonprobability sample.
13) A population mean is an example of a statistic.
14) A sample median is an example.
100) Medicare would like to test the hypothesis that the average monthly rate for one-bedroom assisted-living facility is equal to $3,300. A random sample of 12 assisted-living facilities had an average rate of $3,690 per month. The standard deviation for this sample was $530. Medicare would like to set α.
137) The percentage of companies that use social-media tools and technologies has been increasing over the past several years. A random sample of 170 companies found that 78 of them use social-media tools and technologies. Determine the 80% confidence interval for this sample.
138) The percentage of companies that use social-media.
75) Taylor's Mill is a neighborhood comprised of 185 homes. According to the website Zillow, the average market value of the homes in this neighborhood is $418, 300 with a standard deviation of $36,500. What is the standard error for a random sample of 32 homes from this neighborhood?
A) $4,153.87
B).
31) Increasing the sample size will reduce the margin of error for a given confidence level.
32) A sample proportion equal to 0.50 will require the smallest sample size to achieve a particular margin of error for a confidence interval for the proportion.
33) If a pilot sample is not available, it.
143) According to Pew Research Center, 83% of U.S. adults are using the Internet in January 2012. To verify this percentage, a random sample of 150 adults was selected of which 137 use the Internet. Determine the interval that contains 95% of the sample proportions from this sampling distribution and.
86) A random sample of 130 mortgages in the state of Mississippi was randomly selected. From this sample, 14 were found to be delinquent on their current payment. The approximate standard error of the proportion for this sample is ________.
A) 0.0272
B) 0.0492
C) 0.0560
D) 0.0627
87) A random sample of 130 mortgages.
11) The hypothesis statement H0: μ = 90 is an example of a one-tail hypothesis test.
12) Failing to reject the null hypothesis and accepting the null hypothesis do not refer to the same conclusion.
13) Hypothesis testing relies on proof by contradiction where we assume that the alternative hypothesis is true.
116) Tire Kingdom installs automobile tires on a first-come first-served basis. A random sample of 70 customers experienced an average wait time of 102.7 minutes. Assume that the standard deviation of total wait time for all customers is 17.0 minutes. Determine the 95% confidence interval for this sample.
117) Suppose a.
140) The power of the hypothesis test is the probability of it
A) correctly rejecting the null hypothesis.
B) incorrectly rejecting the null hypothesis.
C) correctly rejecting the alternative hypothesis.
D) incorrectly rejecting the alternative hypothesis.
141) AT&T would like to test the hypothesis that the average revenue per retail user for Verizon Wireless customers.
120) Many hotel chains that offer free Wi-Fi service to their customers have experienced increasing demand for Internet bandwidth and increasing costs. Marriott International would like to test the hypothesis that the proportion of customers that are carrying two Wi-Fi devices exceeds 0.40. A random sample of 130 Marriott customers.
115) The Affordable Care Act is a healthcare reform bill that President Obama signed into law on March 23, 2010. This bill is also known as "ObamaCare". A survey conducted by Jackson & Coker in September 2011 found that only 13% of doctors support this legislation. To validate these findings,.
66) A random sample of 17 hotels in Boston had an average nightly room rate of $165.40 with a sample standard deviation of $21.70. The critical value for a 98% confidence interval around this sample mean is ________.
A) 2.921
B) 2.898
C) 2.567
D) 2.583
67) A random sample of 17 hotels in Boston.
46) Steve's average golf score at his local course is 93.6 from a random sample of 34 rounds of golf. Assume that the population standard deviation for his golf score is 4.2. The 90% confidence interval around this sample mean is ________.
A) (89.0, 98.3)
B) (90.5, 96.7)
C) (93.2, 94.0)
D) (92.4, 94.8)
47).
36) A ________ is a single value that best describes the population of interest.
A) confidence interval
B) point estimate
C) confidence level
D) margin of error
37) A ________ for the mean is an interval estimate around a sample mean that provides us with a range of where the true population mean lies.
A) margin.
1) A hypothesis is an assumption about a population parameter such as a mean or a proportion.
2) The alternative hypothesis, denoted by H0, represents the status quo and involves stating the belief that the population parameter is, ≤, =, or ≥ a specific value.
3) The alternative hypothesis, denoted by H1,.
131) According to SNL Kagan, the average monthly cable bill for homes in the U.S. was $78 in 2011. Assume that the standard deviation for monthly cable bills is $8.50. To confirm these results, a random sample of 46 cable subscribers was selected and found to have an average monthly.
76) AutoTrader.com would like to estimate the number of years owners keep the cars that they purchased as a new vehicle. The following data shows the age of seven vehicles that were sold for the first time by their owners.
Using this sample, the 90% confidence interval that estimates the average.
11) The definition of a 90% confidence interval is that we expect that close to 90% of a large number of sample means drawn from a population will produce confidence intervals that include that population's mean.
12) There is no guarantee that every confidence interval taken from a population will include.
106) A local church has a congregation consisting of 480 adult members. The church's administrators would like to estimate the average weekly donation per member per week. A random sample of 90 members was found to have an average donation of $56.70 and a standard deviation of $10.50. The 90%.
121) According to Responsys, the retailer Neiman Marcus sent an average of 534 e-mails to each of their customers in 2011. Assume that the standard deviation for the number of e-mails per customer that year was 122. A random sample of 30 Neiman Marcus customers was selected. What is the.
145) Toll Brothers is a luxury home builder that would like to test the hypothesis that the average size of new homes exceeds 2,400 square feet. A random sample of 36 newly constructed homes had an average of 2,510 square feet. Assume that the standard deviation of the size for.
72) According to Bureau of Labor Statistics, 22.1% of the total part-time workforce in the U.S. was between the ages of 25 and 34 during the 3rd quarter of 2011. A random sample of 80 part-time employees was selected during this quarter. Using the normal approximation to the binomial distribution,.
1) A benefit of point estimates is that they provide information about their accuracy.
2) The point estimate may not equal the true population mean because of the presence of sampling error.
3) The variation in sample means is measured by the standard error of the mean.
4) The purpose of generating a.
126) According to College Board, the average out-of-state tuition for a four-year public college was $20,770 for the 2011-2012 academic year. There are a total of 629 four-year public institutions in the U.S. Assume that the standard deviation for the tuition for these colleges is $2,100. A random sample of.
139) Franklin Township has 730 registered Democrats residing in the voting district. According to the voting records, 37% participated in the last local election. A random sample of 180 registered Democrats was selected. What is the probability that 54 or fewer of these individuals voted in the recent election?
140) Davidson.
150) The management of the Green Bay Packers football team would like to test the hypothesis that the average price of a ticket is less than $225 on the secondary market. A random sample of 40 customers paid an average of $207 for their ticket. Assume that the standard deviation.
80) The Department of Education would like to test the hypothesis that the average debt load of graduating students with a Bachelor's degree is equal to $17,000. A random sample of 34 students had an average debt load of $18,200. It is believed that the population standard deviation for student.
130) Expedia would like to test the hypothesis that the proportion of United Airline flights that arrive on-time is less than 0.80. A random sample of 110 United Airline flights found that 82 arrived on-time. Expedia would like to set α = 0.02. The conclusion for this hypothesis test would.
55) A ________ sample is used when members of the population are chosen to become part of the sample simply because they are easily accessible.
A) cluster
B) convenience
C) probability
D) stratified
56) The average weight of the entire batch of the boxes of cereal filled today was 18.03 ounces. A random sample of.
35) A ________ sample is a sample in which each member of the population has a known, nonzero, chance of being selected for the sample.
A) systematic
B) simple random
C) probability
D) convenience
36) A ________ sample is a sample in which every member of the population has an equal chance of being chosen.
A).
143) The Centers for Disease Control and Prevention reported that 19% of U.S. adults are cigarette smokers. A random sample of 160 adults contained 42 smokers. Use a 90% confidence interval to confirm the findings of the Centers for Disease Control and Prevention.
144) The U.S. Department of Transportation would like.
