stats

____% of the data are less than or equal to the third quartile 25 50 75 100

75

the five-number summary of test scores in an introductory statistics class is Min=23%, Q1=71%, median=83%, and max = 100% because the shape of the boxplot is skewed because the shape of the boxplot is symmetric

because the shape of the boxplot is skewed

what does the mean measure? shape center variability location of the peak of the distribution

center

quartiles split the ordered data into five equally sized sets. false true

false

which of the following statements concerning areas under the standard normal curve is true? if a z-score is negative, the area to it's right is greater than 0.5 if the area to the right of a z-score is less than 0.5, the z-score is negative if a z-score is positive, the area to its left is less than 0.5

if a z-score is negative, the area to it's right is greater than 0.5

when finding Q1 and Q3, if n is even, what should you do with the median value? include it in both the lower half of the ordered data and the upper half of the ordered data. average it with the minimum and the maximum of the data set it splits the ordered data in half, but is not one of the data values, so don't do anything leave it out of both the lower half and the upper half of the data

it splits the ordered data in half, but is not one of the data values, so don't do anything

when finding Q1 and Q3, if n is odd, what should you do with the median value? include it in both the lower half of the ordered data and the upper half of the ordered data. average it with the minimum and the maximum of the data set it splits the ordered data in half, but is not one of the data values, so don't do anything leave it out of both the lower half and the upper half of the data

leave it out of both the lower half and the upper half of the data

rachael got a 550 on the GRE. If GRE scores are normally distributed and have a mean u=600 and the SD is 30, what is true about other test takers? more than 50% of test takers scored higher than rachael more than 50%of test takers scored lower than rachael exactly 50% of test takers scored higher than rachael less than 50% scored higher than rachael

more than 50% of test takers scored higher than rachael

what is the first step in finding the quartiles? compute the mean order the data find the middle observation in the set

order the data

what is the first thing you should do when finding the median? order the data determine whether n is even or odd find the middle of the data set

order the data

If n is even, what is the median? the average of all the data the middle observation of the ordered data

the average of the middle two observations of the ordered data

what does the second quartile correspond to? the median the mean

the median

what does Q1 correspond to the median of the lower half of the data the median of the upper half of the data the mean of the lower half of the data the mean of the upper half of the data

the median of the lower half of the data

what does Q3 correspond to? the median of the lower half of the data the median of the upper half of the data the mean of the lower half of the data the mean of the upper half of the data

the median of the upper half of the data

If n is odd, what is the median? the average of all the data the middle observation of the ordered data the average of the middle three observations

the middle observation of the ordered data

which one of the following is not a correct statement about the standard deviation? the standard deviation measures the variability of data about the mean the standard deviation can be any positive of negative number the standard deviation is not resistant to outliers the standard deviation has the same unit of measure as the original observations

the standard deviation can be any positive of negative number

what does the median represent? the balance point of the data the distance from the smallest value to the largest value of a data set the value that cuts the ordered data in half

the value that cuts the ordered data in half

why is plotting your data so important? to discover whether the data are categorical or quantitative to aid in computing the mean, median, and standard deviation to decide which measures of center and spread to use

to decide which measures of center and spread to use

the unit of measure for the median is the same as the unit of measure of the data. true false

true

the standard deviation measure the ____ of the data about the mean. dispersion average variability median

variability

graphically, what does the median represent? a value that vertically cuts the area of a histogram in half the distance from the smallest value to the largest value of a data set the balance point of the data

a value that vertically cuts the area of a histogram in half

outliers affect the mean range standard deviation all of the above

all of the above

mean is a measure of the ____ of the dataset average range skew middle

average