3. A teacher was looking through her grade book at her students' test scores. Which score in the data set would be considered an outlier?\begin{tabular}{|c|c|c|c|c|}\hline \multicolumn{5}{|c|}{ Test Scores } \\\hline 87 & 78 & 90 & 81 & 100 \\\hline 93 & 82 & 87 & 45 & 74 \\\hline\end{tabular}A 45B 74C 78D 81
Q. 3. A teacher was looking through her grade book at her students' test scores. Which score in the data set would be considered an outlier?\begin{tabular}{|c|c|c|c|c|}\hline \multicolumn{5}{|c|}{ Test Scores } \\\hline 87 & 78 & 90 & 81 & 100 \\\hline 93 & 82 & 87 & 45 & 74 \\\hline\end{tabular}A 45B 74C 78D 81
List test scores: List all the test scores in ascending order. 45,74,78,81,82,87,87,90,93,100
Calculate IQR: Calculate the interquartile range (IQR).First, find the median, which is the average of the 5th and 6th scores: (82+87)/2=84.5Then, find the medians of the first half and the second half to get Q1 and Q3.First half: 45,74,78,81,82. Median (Q1) is 78.Second half: 87,87,90,93,100. Median (Q3) is 90.IQR=Q3−Q1=90−78=12