BStats I (Chapters 1-3)
The 75<sup>th</sup> percentile in this data set is 30 minutes.
Season's Pizza delivers food items to homes in their local area. The following box-and-whisker plot describes the distribution for delivery times in minutes.
7
The following frequency distribution displays the daily sales of muffins at Avalon Bakery. Number Sold......................Frequency What is the width of each class in this distribution?
descriptive statistics.
According to climate data recorded since 1884, the average annual snowfall in Philadelphia is 22.3 inches. This value is an example of ________. (Question 8)
5.5
The following data shows the number of home runs hit by the top 12 home run hitters during a recent Major League Baseball season. 43 41 39 39 38 37 37 36 34 33 33 32 The interquartile range is ________.
line chart
The following graph shows the average price of LCD TVs from 2005 until 2012. This graph is an example of a ________.
Historically, the average price of LCD TVs tends to decrease.
The following graph shows the average price of LCD TVs from 2005 until 2012. Which one of the following statements is correct?
scatter plot
The following graph shows the curb weight of seven cars, in pounds, along with their corresponding highway miles per gallon. This graph is an example of a ________.
As the square footage of the home increases, the monthly heating cost tends to decrease.
The following graph shows the square footage of 10 homes along with their corresponding heating cost for the most recent month. Which one of the following statements is not correct?
18.5
The following table represents the number of minutes that 20 airline passengers had to wait in order to pass through security along with the frequency in each class.
2.6
The following table shows a frequency distribution of the number of MacBook Air laptops sold per day at a particular Best Buy. # of Laptops.....................................Frequency 0..............................................................2 1...............................................................5 2..............................................................3 3..............................................................8 4..............................................................5 5..............................................................2 What is the mean number of MacBook Air laptops sold per day?
2.6
The following table shows a frequency distribution of the number of MacBook Air laptops sold per day at a particular Best Buy. What is the mean number of MacBook Air laptops sold per day?
Time series
The following table shows the number of bagels sold at the Avalon Coffee and Bagel over the past seven days. Monday..................69 Tuesday..................75 Wed..........................78 Which of the following data types best describe these values?
Clustered Bar Charts
The following table shows the percentage of e-mails that are sent each day of the business week according to an Intermedia survey. Day........................Percentage Which of the following best displays this data?
pie chart
The following table shows the percentage of e-mails that are sent each day of the business week according to an Intermedia survey. Day...................Percentage Which of the following best displays this data?
Time Series
The following table shows the stock price for Facebook at the end of the past four quarters. Which of the following data types best describe these values?
Information
is (are) derived from facts for the purpose of making decisions.
population
A ________ represents all possible subjects of interest.
Inferential Statistics
Bridgestone would like to estimate the average tread life of a particular brand of automobile tire. Fifty customers who have purchased this tire are sampled and asked about the tread life of their tires. This is an example of using ________.
Chapter 1
Chapter 1
Chapter 2
Chapter 2
Chapter 3
Chapter 3
Advertising
Collecting data about the television viewers for the Summer Olympics is an example of using statistics in the field of
coefficient of variation
Comparing the consistency between two data sets when their means are very different is best done with the ________.
Parameter
Data that describe a characteristic about a population is known as a ________.
Marketing Research
Gathering information from potential customers in an effort to determine their preferences is an example of using statistics in the field of
True
True of False: A weighted mean allows you to assign more weight to certain values and less weight to others.
False
True of False: One disadvantage of using the median is that it can be heavily influenced by outliers.
Operations
Using quality control techniques to test the salt content of pretzels before they are packaged for the consumer is an example of using statistics in the field of
Nominal and Ordinal
Which levels of measurement are considered qualitative data?
Your last name
Which of the following is an example of qualitative data?
The mean is less than the median
Which one of the following statements is true for a left-skewed distribution?
Sample
A ________ is a portion of a population that is representative of the population from which it is selected. (Question 6)
frequency distribution
A ________ is a table that shows the number of data observations that fall into specific intervals.
biased
A ________ sample does not represent the intended population and can lead to distorted findings.
Interval
A car dealership performs a credit check on a potential customer. According to the credit bureau, the customer's credit score is 710. This is an example of ________ data.
7
A data set has 60 observations with a minimum value equal to 30 and a maximum value equal to 72. The estimated class width using the 2k ≥ n rule to determine the number of classes is
it is highly influenced by outliers.
A disadvantage of using the range as a measure of variability is that ________.
Focus Groups
A method of gathering data when individuals are paid to discuss their attitudes towards products or services in a group setting controlled by a moderator is known as ________.
Surveys
A method of gathering data when people are asked a series of questions that can be administered by e-mail, via the Web, face-to-face or over the telephone, is known as ________.
Ordinal
A property of ________ data is that the differences between categories are not meaningful and, therefore, cannot be measured.
.96
A random sample of 2008 used cars for sale on the market has an average mileage of 71,420 miles with a sample standard deviation of 9,470 miles. The z-score for a used car with 80,500 miles in this sample is ________.
Nominal
A respondent of a survey indicates that he is a resident in the state of Ohio. This is an example of ________ data.
Ordinal
A respondent of a survey is asked whether their most recent dining experience was excellent, good, fair, or poor. The person indicates that the experience was "good". This is an example of ________ data.
Use equal-size classes.
Consider the following frequency distribution. Number of Customers...................Frequency Which rule for constructing a frequency distribution using grouped quantitative data has been violated?
No rule has been violated.
Consider the following frequency distribution. Number of minutes.........frequency Which rule for constructing a frequency distribution using grouped quantitative data has been violated? (Question 9)
46%
Porter Automotive is a car dealership that sells Buicks and Hondas. The following data shows the number of buyers this month according to the brand of car they purchased as well as their age group. The percentage of buyers who are under 40 old in this data is _____.
contingency table
Porter Automotive is a car dealership that sells Buicks and Hondas. The following data shows the number of buyers this month according to the brand of car they purchased as well as their age group. This data is an example of a ________.
Buick owners tend to be older than Honda owners.
Porter Automotive is a car dealership that sells Buicks and Hondas. The following data shows the number of buyers this month according to the brand of car they purchased as well as their age group. Which one of the following statements is true based on the data?
$1,600 to $3,400
Suppose the dealer incentive per vehicle for Honda's Acura brand in 2012 is thought to be bell-shaped and symmetrical with a mean of $2,500 and a standard deviation of $300. Based in this information, what interval of dealer incentives would we expect approximately 99.7% of vehicles to fall within?
Median
The ________ is found by first determining the index point, i = 0.5(n), where n is the number of data points.
Standard Deviation
The ________ is the most common and most important measure of variability in the field of statistics.
median
The ________ is the value in the data set for which half the observations are higher and half the observations are lower.
Variance
The ________ measures the variability, or spread, of the data points in a set around the set's mean.
13.7%
The average salary for a sales representative in a medical billing company is $46,600 with a standard deviation of $6,400. The coefficient of variation for salaries at this company is
73.5
The daily high temperature in Philadelphia over an eight-day period is shown below. 69 77 70 81 84 86 69 70 The median for this data set is ________.
69 and 70
The daily high temperature in Philadelphia over an eight-day period is shown below. 69 77 70 81 84 86 69 70 The mode for this data set is ________.
The second quartile in the data set is $160 per night.
The following box-and-whisker plot shows the distribution for three-star hotel rates per night in New York City.
The Hyundai Accent has a lower average market price than the Nissan Versa.
The following chart shows the average market price for five brands of cars in March 2013. Which of the following statements is not correct?
29.5
The following data represent the wait time, in minutes, for customers calling Comcast technical support. 14 2 13 7 24 19 12 16 6 9 13 The upper limit for determining outliers for a box-and-whisker plot is ________ minutes.
20.4
The following data represents the ages of a household that consists of five people. 39 37 12 7 7 Assuming this household represents a population, the mean of this data set is ________.
6.0
The following data represents the number of Sony TVs sold per day at a particular Costco over a random sample of five business days. 9 2 7 7 5 The mean of this sample is ________.
7
The following data represents the number of Sony TVs sold per day at a particular Costco over a random sample of five business days. 9 2 7 7 5 The mode of this sample is ________.
2.0
The following data represents the number of Sony TVs sold per day at a particular Costco over a random sample of five business days. 9 2 7 7 5 The standard deviation of this sample is ________.
4.38
The following data set represents the age of a random sample of cars on the road today. 1 3 3 7 10 12 The standard deviation of this sample is ________.
19.2
The following data set represents the age of a random sample of cars on the road today. 1 3 3 7 10 12 The variance of this sample is ________.
Experiments
The manager at the local Ruby Tuesday's restaurant wanted to investigate the effect of music on the average revenue per customer. Each night for one month, fast-paced music was played. The following month, slow-paced music was played every night. The average revenue per customer for each month was compared. This method of gathering data is known as ________.
50<sup>th</sup>
The median is the ________ percentile in the data set.
Descriptive Statistics
The proportion of customers that rate their latest airline experience as "excellent" is an example of ________.
Cross Sectional
The results from a survey that collected annual household income is shown in the following table. Household Income................# of households Which of the following data types best describe these values?
correlation coefficient
The sample ____________ measures both the direction and strength of the linear relationship between two variables.
between -1.0 and +1.0
The sample correlation coefficient can be equal to any value __________.
False
True of False: Because outliers are extreme values that could distort the analysis, they should always be eliminated from the data set.
True
True of False: Outliers are extreme values above or below the mean that require special consideration.
True
True of False: Some data sets may not have a mode.
True
True of False: The central tendency is where the majority of the data points can be found in a histogram.
True
True of False: The mean is a convenient measurement for summarizing a data set with a single value.
True
True of False: The mean of a data set is also known as the average value.
False
True of False: The median of a data set is found by adding all the values in the data set and then dividing the result by the number of observations.
False
True of False: The mode is the most useful measure of central tendency for a data set.
False
True of False: The range is a measure of central tendency.
True
True of False: There can be more than one mode in a data set.
False
True of False: When calculating a weighted mean, the weights need to sum to 1.0.
True
True of False: When the index point, i, is not a whole number, round i up to the next highest whole number to find the position of the median in a sorted data set.
False
True of False: When there are an odd number of data values, the median is halfway between the two middle values in the data set.
False
True of False: When there is an even number of data values, the median is always the middle value in the data set.
True
True of False: When you rely on the mean to summarize many data values, you lose important information about the original data.
False
True of False? In a quality control setting, the sample mean provides enough evidence to determine if a process is working properly.
True
True of False? Measures of variability show how much spread is in your data.
False
True of False? The sample variance is a biased estimator of the population variance because we would expect the average of many sample variances taken from a population would be equal to the true population variance.
True
True of False? The standard deviation of a data set can never be negative.
False
True of False? The unit of measure for the variance is the same as the unit of measure for the original data.
False
True of False? Using n — 1 in the denominator for the sample variance is a much better estimate of the true population variance when compared to dividing by n.
False
True of False? When all of the data values in the sample are the same, the sample standard deviation equals 1.0.
True
True of False? When sample means of two data sets are very different, comparing sample standard deviations can be misleading.
the mean is greater than the median
Which one of the following statements is true for a right-skewed distribution?
Qualitative
________ data use descriptive terms to measure or classify something of interest.
Central Tendency
________ is a single value used to describe the center point of a data set.
