Statistics Study Guide

Find the mean of the second grade heights. Round to the nearest tenth.

Answer explanation

Remember to add all the numbers and divide by the number of items you added. This is the average.

Find the mode of the second grade heights.

• 45

• 49

• 51

• 53

• 54

Answer explanation

The number that repeats the most

What is the range of the data set 75, 87, 49, 68, 75, 84, 98

Answer explanation

Highest number minus lowest number.

What is the median of the data set 55, 47, 38, 66, 56, 64, 44, 63, 39?

Answer explanation

Put numbers in order from least to greatest and find the number in the middle.

What is the mean of the data set 18, 24, 17, 21, 24, 16, 29, 18? Round to the nearest tenth.

What is the IQR of the data set 12, 24, 17, 21, 24, 16, 29, 18?

Answer explanation

1. Put numbers in order from least to greatest.

2. Find the middle number.

3. Find the median of the lower group of numbers (lower quartile).

4. Find the the median of the upper group of numbers (upper quartile).

5. Upper quartile minus lower quartile.

The values (in thousands of dollars) of homes sold by a

realtor are shown in the dot plot. How many homes sold for more than $250,000?

Answer explanation

Count the number of X's above numbers greater than $250,000.

The values (in thousands of dollars) of homes sold by a

realtor are shown in the dot plot. How many homes sold for less than $250,000?

• 1

• 2

• 3

• 4

Answer explanation

Count the number of X's above numbers greater than $250,000.

Two dot plots are graphed. Which statement about these data sets is most likely true?

• The median of Data Set 2 is less than the median of Data Set 1.

• The range of Data Set 2 is greater than the range of Data Set 1.

• The modes of Data Sets 1 and 2 are equal.

• The mean of Data Set 2 is greater than the mean of Data Set 1.

Identify Q₁ from the given box plot.

Answer explanation

Start of the box.