Statistics multiple choice
σ2
The symbol for population variance is
s
The symbol for sample standard deviation is
S2
The symbol for sample variance is
Range
Which measure of variation is very sensitive to extreme values?
The units of variance are squared. Its units are meaningless.
Why is the standard deviation used more frequently than the variance?
No, the result from part (a) could not be the actual number of adults who said that secondhand smoke is "very harmful" because a count of people must result in a whole number.
A polling company reported that 57% of 1018 surveyed adults said that secondhand smoke is "very harmful." Complete parts (a) through (d) below. Could the result from part (a) be the actual number of adults who said that secondhand smoke is "very harmful" question mark Why or why not?
If percentages are used, the sum should be 100%. If proportions are used, the sum should be 1.
After constructing a relative frequency distribution summarizing IQ scores of college students, what should be the sum of the relative frequencies?
If the device eliminated all bike thefts comma it would reduce the odds of bike theft by 100 % comma so the 350 % figure is misleading.
An ad for a device used to discourage bike thefts stated that "This device reduces your odds of bike theft by 350 percent." What is wrong with this statement?
subtracting a lower class limit from the next consecutive lower class limit
Class width is found by _______.
A discrete data set because there are a finite number of possible values.
Determine whether the given value is from a discrete or continuous data set. When a car is randomly selected, it is found to have 2 doors.
It is from a continuous data set because the number of possible values is infinite and not countable.
Determine whether the given value is from a discrete or continuous data set. When a van is randomly selected, it is found to have a weight of 1892.7 kg.
When calculating the population standard deviation, the sum of the squared deviation is divided by N, then the square root of the result is taken. When calculating the sample standard deviation, the sum of the squared deviations is divided by nminus1, then the square root of the result is taken.
Describe the difference between the calculation of population standard deviation and that of sample standard deviation. Let N be the number of data entries in a population and n be the number of data entries in a sample data set. Choose the correct answer below.
A discrete data set because there are a finite number of possible values nothing
Determine whether the value given below is from a discrete or continuous data set. In a test of a method of gender selection comma 679 couples used the XSORT method and 414 of them had baby girls.
The range is found by subtracting the minimum data entry from the maximum data entry.
Explain how to find the range of a data set. What is an advantage of using the range as a measure of variation? What is a disadvantage? Explain how to find the range of a data set. Choose the correct answer below.
It uses only two entries from the data set.
Explain how to find the range of a data set. What is an advantage of using the range as a measure of variation? What is a disadvantage? What is a disadvantage of using the range as a measure of variation?
It is easy to compute.
Explain how to find the range of a data set. What is an advantage of using the range as a measure of variation? What is a disadvantage? What is an advantage of using the range as a measure of variation?
The standard deviation is the positive square root of the variance. The standard deviation and variance can never be negative. Squared deviations can never be negative.
Explain the relationship between variance and standard deviation. Can either of these measures be negative? Explain.
When given a data set, one would have to determine if it represented the population or if it was a sample taken from the population. If the data are a population, then σ is calculated. If the data are a sample, then s is calculated.
Given a data set, how do you know whether to calculate σ or s?
relative frequency
In a _______ distribution, the frequency of a class is replaced with a proportion or percent.
126.56.
Listed below are the top 10 annual salaries (in millions of dollars) of TV personalities. Find the range, variance, and standard deviation for the sample data. Given that these are the top 10 salaries, do we know anything about the variation of salaries of TV personalities in general? 40 38 37 31 19 18 15 14 13.8 12.9 The variance of the sample data is ---------.
No, because the sample is not representative of the whole population.
Listed below are the top 10 annual salaries (in millions of dollars) of TV personalities. Find the range, variance, and standard deviation for the sample data. Given that these are the top 10 salaries, do we know anything about the variation of salaries of TV personalities in general? 40 38 37 31 19 18 15 14 13.8 12.9 Is the standard deviation of the sample a good estimate of the variation of salaries of TV personalities in general?
11.25
Listed below are the top 10 annual salaries (in millions of dollars) of TV personalities. Find the range, variance, and standard deviation for the sample data. Given that these are the top 10 salaries, do we know anything about the variation of salaries of TV personalities in general? 40 38 37 31 19 18 15 14 13.8 12.9 The standard deviation of the sample data is $ ------- million.
variance
The square of the standard deviation is called the _______.
σ
The symbol for population standard deviation is
