1. The mode is 70, as it appears most frequently (4 times).
2. The median is 70, found by ordering the data and selecting the middle value (the 8th value in the ordered list of 15 values).
3. The mean is calculated as the sum of all values divided by the number of values: (60 + 65 + 65 + 65 + 70 + 70 + 70 + 70 + 75 + 75 + 75 + 80 + 80 + 85 + 90) / 15 = 1095 / 15 = 73.
4. The range is the difference between the highest and lowest values: 90 - 60 = 30.
5. The interquartile range (IQR) is Q3 - Q1. Q1 (median of the first half) is 65, Q3 (median of the second half) is 80, so IQR = 80 - 65 = 15.
6. The standard deviation is approximately 8.37, calculated using the formula for sample standard deviation.
7. The variance is the square of the standard deviation: approximately 70.06.
8. The coefficient of variation is (standard deviation / mean) * 100% ≈ (8.37 / 73) * 100% ≈ 11.47%.
9. The data is slightly skewed to the right, as the mean (73) is greater than the median (70).
10. The 90th percentile is approximately 85, meaning 90% of the data falls below this value.
Parent Tip: Review the logic above to help your child master the concept of algebra with pizzazz page 34.
