Questions and Answers of Elementary Statistics

Indicate whether the observational study used is cross-sectional, retrospective, or prospective.Phase II of the Nurses’ Health Study was started in 1989 with 116,000 female registered nurses. The
Indicate whether the observational study used is cross-sectional, retrospective, or prospective.Samples of subjects with and without heart disease were selected, and then researchers looked back in
Listed below are the numbers of unprovoked shark attacks worldwide for the last several years. Why is it that a dotplot of these data would not be very effective in helping us understand the data?
Indicate whether the observational study used is cross-sectional, retrospective, or prospective.The Framingham Heart Study was started in 1948 and is ongoing. Its focus is on heart disease.
Identify what is wrong.In recent years, the numbers of cell phones and the numbers of pirates have both increased, so there is a correlation, or association, between those two variables. Therefore,
Identify which of these designs is most appropriate for the given experiment: completely randomized design, randomized block design, or matched pairs design.Lunesta is a drug designed to treat
Use the sample data to construct a scatterplot. Use the first variable for the x-axis. Based on the scatterplot, what do you conclude about a linear correlation?Listed below are the cellular data
Identify what is wrong.In the years following the end of World War II, it was found that there was a strong correlation, or association, between the number of human births and the stork population.
Identify what is wrong.The software package StatCrunch coordinated a “Future Optimism Survey” that included this question: Do you expect to be better off than your parents were over their
Use the sample data to construct a scatterplot. Use the first variable for the x-axis. Based on the scatterplot, what do you conclude about a linear correlation?The table below lists amounts of tar
Identify what is wrong.Twelve nutritionists are each paid $100,000 to try a new celebrity diet on ten of their clients and then write a report summarizing the results. Based on the sample results, it
Answer the given questions, which are related to percentages.In an actual ad for the Club, a device used to discourage car thefts, it was stated that “The Club reduces your odds of car theft by
Use the sample data to construct a scatterplot. Use the first variable for the x-axis. Based on the scatterplot, what do you conclude about a linear correlation?The table lists actual high
IQ scores of adults are normally distributed. If a large sample of adults is randomly selected and the IQ scores are illustrated in a histogram, what is the shape of that histogram?
The population of IQ scores of adults is normally distributed. If we obtain a voluntary response sample of 5000 of those IQ scores, will a histogram of the sample be bell shaped?
Use the indicated data to construct the frequency distribution.Listed below are the first 50 Chicago commute times from Data Set 31. Construct a frequency distribution. Use a class width of 15
Use the sample data to construct a scatterplot. Use the first variable for the x-axis. Based on the scatterplot, what do you conclude about a linear correlation?The table lists pulse rates (beats per
Using a package of purchased chocolate chip cookies, each student should be given two or three cookies. Proceed to count the number of chocolate chips in each cookie. Not all of the chocolate chips
Listed below are radiation levels (W/kg) from Samsung Galaxy cell phones (based on data from Samsung). Why does it not make sense to construct a histogram for this data set?0.87 1.18 1.47
Construct the time-series graph.Listed below are women’s median earnings as a percentage of men’s median earnings for recent years beginning with 1997 (listed in order by row). Is there a trend?
Construct the time-series graph.Listed below are the numbers of home runs in Major League Baseball for each year beginning with 1993 (listed in order by row). Is there a trend? 4030 3306 4081 4962
For each student in the class, measure shoe print length and height. Construct a scatterplot of the paired data. Does there appear to be a correlation? Explain.
Listed below are maximum speeds (km/h) of randomly selected roller coasters in the United States. Find the mean. 70 76 97 81 57 151 194 65 117 65 45 105
Use the given categorical data to construct the relative frequency distribution.Here are the countries with the five highest estimated costs of software piracy: United States ($9.1 billion), China
Education Week magazine published a list consisting of the mean teacher salary in each of the 50 states for a recent year. If we add the 50 means and then divide by 50, we get $56,479. Is the value
Each student should obtain a sample of pennies. For each penny, find its age by subtracting the year that the penny was produced from the current year. Those ages should be combined into one data
Listed below are sorted weights (g) of a sample of M&M plain candies randomly selected from one bag. Use the range rule of thumb to estimate the value of the standard deviation of all 345
Each student should obtain a sample of data from a line of people waiting for a service. For each person, record the arrival time, the time waiting in line, and the time it took to complete the
In a recent year, applicants to medical schools achieved scores on the Medical College Admission Test (MCAT) with a mean of 504.7 and a standard deviation of 9.4. Identify the MCAT scores that are
A larger sample of 92 roller coaster maximum speeds has a mean of 85.9 km/h and a standard deviation of 28.7 km/h. What is the z score for a speed of 34 km/h? Does the z score suggest that the speed
Record the times that cars are parked at a gas pump, and describe important characteristics of those times.
For the sample of 92 roller coaster maximum speeds, approximately how many of those speeds are less than Q3?

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