Statistics Test 1
Among the 2286 respondents, 1096 said that they only play hockey. What percentage of respondents said that they only play hockey?
47.94%
Determine whether the value given below is from a discrete or continuous data set: The volume of cola in a can is 11.6 oz.
A continuous data set because there are infinitely many possible values and those values cannot be counted.
Determine whether the given value is from a discrete or continuous data set: When a car is randomly selected, it is found to have 3 wipers.
A discrete data set because there are a finite number of possible values.
An editorial criticized a chart caption that described a dental rinse as one that "reduces thethe chance of plaque on teeth by over 400 percent." What is wrong with this statement?
A reduction of 100 % would eliminate all plaque, so it is not possible to reduce it by more than 100%.
Which of the following is associated with a parameter?
Data that were obtained from an entire population.
Which of the following would be classified as categorical data?
Hair color
Determine whether the sampling method described below appears to be sound or is flawed: In a survey of 800 human resource professionals, each was asked about the importance of the education of a job applicant. The survey subjects were randomly selected by pollsters from a reputable market research firm.
It appears to be sound because the data are not biased in any way.
In a survey of 693 subjects, each was asked how often he or she watched TV. The survey subjects were internet users who responded to a question that was posted on a news website.
It is flawed because it is a voluntary response sample.
Determine whether the given value is from a discrete or continuous data set: When a limo is randomly selected, it is found to have enough room to seat 6 people.
It is from a discrete data set because the number of possible values is finite or countable.
Could the result from part (a) be the actual number of adults who said that they play baseball? Why or why not?
No, the result from part (a) could not be the actual number of adults who said that they play baseball because a count of people must result in a whole number.
Based on a study of weights of men and women who watch TV, a researcher concludes that watching television causes people to gain weight. Do you agree with this conclusion?
No. There may be a relationship between watching television and weight gain, but that does not mean that one causes the other.
Which of the following consists of discrete data?
Number of suitcases on a plane
Which of the following is NOT a voluntary response sample?
Quiz scores from a college level statistics course are analyzed to determine student progress.
Determine whether the given value is a statistic or a parameter: A sample of professors is selected and it is found that 45% own a television.
Statistic because the value is a numerical measurement describing a characteristic of a sample.
What is the exact value that is 27% of 2286?
The exact value is 617.22
Determine whether the given description corresponds to an observational study or an experiment. In a study of 356 women with a particular disease, the subjects were monitored with an EEG while asleep.
The given description corresponds to an observational study.
Determine whether the given value is a statistic or a parameter: A homeowner measured the voltage supplied to his home on 30 different dayson 30 different days, and the average (mean) value is 141.1 volts.
The given value is a statistic for the year because the data collected represent a sample.
What does it mean for the findings of a statistical analysis of data to be statistically significant?
The likelihood of getting these results by chance is very small.
A particular country has 40 total states. If the areas of 30 states are added and the sum is divided by 30, the result is 176,881square kilometers. Determine whether this result is a statistic or a parameter.
The result is a statistic because it describes some characteristic of a sample.
Determine whether the given value is a statistic or a parameter: A sample of 1603 women showed that 41 % go to school.
The value is a statistic because it is a numerical measurement describing some characteristic of a sample.
Determine whether the source given below has the potential to create a bias in a statistical study: A certain medical organization tends to oppose the use of meat and dairy products in our diets, and that organization has received hundreds of thousands of dollars in funding from an animal rights foundation.
There does appear to be a potential to create a bias. There is an incentive to produce results that are in line with the organization's creed and that of its funders.
What is the goal of learning statistics?
To learn to distinguish between statistical conclusions that are likely to be valid and those that are seriously flawed
In a study of a weight loss program, 40 subjects lost a mean of 2.9 lbs after 12 months. Methods of statistics can be used to show that if this diet had no effect, the likelihood of getting these results is roughly 5 chances in 1000. Does the weight loss program have statistical significance? Does the weight loss program have practical significance?
Yes because the results are unlikely to occur by chance. No, someone starting a weight loss program would likely want to lose considerably more than 2.9 lb
If we are collecting sample data for a study, the _______ that we choose can greatly influence the validity of our conclusions. For example, we can use sound statistical methods to analyze data in voluntary response samples, but the results are not necessarily valid.
sampling method
Refer to the given table of measurements below. Is there some meaningful way in which the IQ scores are matched with the corresponding brain volumes? If they are matched, does it make sense to use the difference between each IQ score and brain volume that is in the same column? Why or why not?
Yes, each IQ score is matched with the brain volume in the same column, because they are measurements obtained from the same person. No, it does not make sense to use the difference between each IQ score and brain volume in the same column, because IQ scores and brain volumes use different units of measurement.