Questions: Which data set has an outlier? 6,13,13,15,15,18,18,22 4,4,4,8,9,9,11,18 2,3,5,7,8,8,9,10,12,17 3,6,7,7,8,8,9,9,9,10
Transcript text: Which data set has an outlier?
$6,13,13,15,15,18,18,22$
$4,4,4,8,9,9,11,18$
$2,3,5,7,8,8,9,10,12,17$
$3,6,7,7,8,8,9,9,9,10$
Solution
Solution Steps
To determine which data set has an outlier, we can use the Interquartile Range (IQR) method. The steps are as follows:
Calculate the first quartile (Q1) and third quartile (Q3) of each data set.
Compute the IQR as Q3 - Q1.
Determine the lower bound as Q1 - 1.5 * IQR and the upper bound as Q3 + 1.5 * IQR.
Identify any data points that fall outside these bounds as outliers.
Step 1: Calculate Quartiles and IQR for Each Data Set
For each data set, we calculate the first quartile (\(Q1\)) and the third quartile (\(Q3\)), and then compute the interquartile range (IQR) as \(Q3 - Q1\).
Data Set 1: \([6, 13, 13, 15, 15, 18, 18, 22]\)
\(Q1 = 13\)
\(Q3 = 18\)
\(\text{IQR} = 18 - 13 = 5\)
Data Set 2: \([4, 4, 4, 8, 9, 9, 11, 18]\)
\(Q1 = 4\)
\(Q3 = 9\)
\(\text{IQR} = 9 - 4 = 5\)
Data Set 3: \([2, 3, 5, 7, 8, 8, 9, 10, 12, 17]\)
\(Q1 = 5\)
\(Q3 = 10\)
\(\text{IQR} = 10 - 5 = 5\)
Data Set 4: \([3, 6, 7, 7, 8, 8, 9, 9, 9, 10]\)
\(Q1 = 7\)
\(Q3 = 9\)
\(\text{IQR} = 9 - 7 = 2\)
Step 2: Determine Outlier Bounds
Using the IQR, we determine the lower and upper bounds for outliers as follows:
Lower Bound: \(Q1 - 1.5 \times \text{IQR}\)
Upper Bound: \(Q3 + 1.5 \times \text{IQR}\)
Data Set 1:
Lower Bound: \(13 - 1.5 \times 5 = 5.5\)
Upper Bound: \(18 + 1.5 \times 5 = 25.5\)
Data Set 2:
Lower Bound: \(4 - 1.5 \times 5 = -3.5\)
Upper Bound: \(9 + 1.5 \times 5 = 16.5\)
Data Set 3:
Lower Bound: \(5 - 1.5 \times 5 = -2.5\)
Upper Bound: \(10 + 1.5 \times 5 = 17.5\)
Data Set 4:
Lower Bound: \(7 - 1.5 \times 2 = 4\)
Upper Bound: \(9 + 1.5 \times 2 = 12\)
Step 3: Identify Outliers
We identify any data points that fall outside the lower and upper bounds as outliers.
Data Set 1:
No outliers since all data points are within \([5.5, 25.5]\).
Data Set 2:
Outlier: \(18\) (since \(18 > 16.5\))
Data Set 3:
Outlier: \(17\) (since \(17 > 17.5\))
Data Set 4:
Outlier: \(3\) (since \(3 < 4\))
Final Answer
Data Set 1: No outliers.
Data Set 2: Outlier is \(18\).
Data Set 3: Outlier is \(17\).
Data Set 4: Outlier is \(3\).
\(\boxed{\text{Data Set 2 has an outlier: } 18}\)
\(\boxed{\text{Data Set 3 has an outlier: } 17}\)
\(\boxed{\text{Data Set 4 has an outlier: } 3}\)