Final answer:
The mean of the annual numbers of deaths from tornadoes in the United States from 1995 through 2015 is approximately 84.48. The median is 54. The range and IQR of the data set are 532 and 43, respectively.
Step-by-step explanation:
To find the mean, add up all the numbers and divide the sum by the total number of values:
30 + 25 + 67 + 130 + 94 + 41 + 40 + 55 + 54 + 35 + 38 + 67 + 81 + 126 + 21 + 45 + 553 + 70 + 55 + 47 + 36 = 1774
Mean = 1774 / 21 = 84.47619047 (rounded to 2 decimal places)
To find the median, arrange the numbers in ascending order and find the middle value:
21, 25, 30, 35, 36, 38, 40, 41, 45, 47, 54, 55, 55, 67, 67, 70, 81, 94, 126, 130, 553
There are 21 numbers, so the median is the 11th value, which is 54.
To find the range, subtract the lowest value from the highest value:
Range = 553 - 21 = 532
To find the IQR (interquartile range), first find the first quartile and the third quartile. The first quartile is the median of the lower half of the data, and the third quartile is the median of the upper half of the data:
21, 25, 30, 35, 36, 38, 40, 41, 45, 47, 54, 55, 55, 67, 67, 70, 81, 94, 126, 130, 553
Lower half: 21, 25, 30, 35, 36, 38, 40, 41, 45, 47
Upper half: 54, 55, 55, 67, 67, 70, 81, 94, 126, 130, 553
First quartile: Median of the lower half = 38
Third quartile: Median of the upper half = 81
Now, subtract the first quartile from the third quartile to find the IQR:
IQR = 81 - 38 = 43