chapter two

Question 1

diff between min and max entries=

Answer 1

range

Question 2

How to find class width

Answer 2

using the range divided by # of
classes (round up answer to nearest 1)

Question 3

Frequency histogram polygon, relative frequency graph, cumulative frequency

Answer 3

Frequency Histogram: Bar graph showing the count of observations per class interval.
Frequency Polygon: Line graph connecting midpoints of class intervals at their frequencies.
Relative Frequency Graph: Similar to a histogram but uses proportions instead of counts.
Cumulative Frequency Graph (Ogive): Line graph showing the total number of observations below each class boundary.

Question 4

How do stem leaf plots work?

Answer 4

The stem is the entry’s leftmost digit(s)
 The leaf is the rightmost digit

Question 5

Skewed means…

Answer 5

direction where tail is leaning

Question 6

What is the empirical rule

Answer 6

tates that, assuming you have a bell-shaped distribution (normal or
symmetric), 68% of data falls between ± 1 s of the mean, 95% falls between ± 2 s of the mean,
99.7% falls between ± 3 s of the mean.
.

Question 7

Interquartile Range (IQR)

Answer 7

Interquartile Range (IQR) = A measure of variation that gives the range of the middle
portion (about half) of the data.
 The difference between the third and first quartiles or IQR = Q3 – Q1
.
 You can use the IQR to identify outliers that fall outside of this range.
 Any data entry less than Q1 1.5(IQR) is an outlier.
 Any data entry greater than Q3 + 1.5(IQR) is an outlier.

Question 8

Standard Score (z-score)

Answer 8

tandard Score (z-score): Represents the number of standard deviations a
given value x falls from the mean μ.