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Median:. Because there is an even number of data values, the median is the mean of the two middle values. 60 + 61. 121. 60.5. =. =. =. 2. 2. EXAMPLE 2. Finding Median, Mode, and Range. Find the median, mode(s), and range of the numbers below. 64 60 64 38 52 65 61 48. SOLUTION.
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Median: Because there is an even number of data values, the median is the mean of the two middle values. 60 + 61 121 60.5 = = = 2 2 EXAMPLE 2 Finding Median, Mode, and Range Find the median, mode(s), and range of the numbers below. 64 60 64 38 52 65 61 48 SOLUTION Write the numbers in order from least to greatest. 38 48 52 60 61 64 64 65 Median
65 – 38 27 = = EXAMPLE 2 Finding Median, Mode, and Range Mode: The number that occurs most often is 64. Range: Find the difference between the greatest and the least values. Range
1 + 8 + 12 + 10 + 45 + 9 +1 + 7 + 6 9 EXAMPLE 3 Choosing the Best Average Dance-a-Thon: You receive the pledge amounts listed below for your participation in a dance-a-thon. Which average best represents the pledge amounts? $1 $8 $12 $10 $45 $9 $1 $7 $6 SOLUTION Find the mean: STEP 1 = $11 The mean suggests that most pledges are greater than they actually are.
The median best represents the pledge amounts. ANSWER EXAMPLE 3 Choosing the Best Average Find the median: 1 1 6 7 8 9 10 12 45 STEP 2 The median is $8. It is the middle value of the nine values. Find the mode: The pledge that occurs most often is $1. STEP 3 The mode suggests that most pledges are less than they actually are.
The median best represents the pledge amounts. ANSWER EXAMPLE 3 Choosing the Best Average Find the range: $45 – $1 = $44 STEP 4 The range suggests that the data are more evenly spaced than they are.
300 + 120 420 21 = = = 20 20 ANSWER The mean cost of the trees is $21. The correct answer is B. EXAMPLE 4 Standardized Test Practice SOLUTION To find the mean cost of the trees, divide the sum of the costs by the total number of trees purchased. Mean
9, 13, 19, 14, 16, 11, 7, 6, 13 18, 52, 23, 79, 66, 17, 20, 10 3. 4. ANSWER ANSWER 13; 13; 13 21.5; no mode; 69 for Examples 2, 3, and 4 GUIDED PRACTICE Find the median, mode(s), and range.
5. What If? ANSWER median for Examples 2, 3, and 4 GUIDED PRACTICE In Example 3, you receive three more pledges of $15, $20, and $22. Which measure best represents the pledge amounts?
What are the mode and median costs of the trees in Example 4? 6. ANSWER 20; 20 for Examples 2, 3, and 4 GUIDED PRACTICE