The ages of a group of athletes are as follows: 18, 16. 18,20, 17, 16, 19, 17, 18, 17 and 13. (a) Find the range of the distribution.
(b) Draw a frequency distribution table for the data.
(ii) standard deviation.
(a) The range of a distribution is the difference between the largest and smallest values. For the given ages of athletes, the largest age is 20 and the smallest age is 13, so the range is
= 20 - 13 = 7.
(b) A frequency distribution table organizes the data by showing how many times each value occurs. Here is the frequency distribution table for the given data:
∑
f = 11∑
fx = 191 ∑
f2
= 3337
Age(x) |
Tally |
Freq (f) |
|
Com. Freq |
fx |
fx2
|
15 16 17 18 19 20 |
I II III III I I |
1 2 3 3 1 1 |
|
1 3 6 9 10 11 |
15 32 51 54 19 20 |
225 512 867 972 361 400 |
(c) The median is the middle value of a distribution. To find the median, we need to put the data in order from smallest to largest. The ordered data is:
13, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 19, 20
Since there are an odd number of values, the median is the middle value, which is 17.
(d) (i) The mean is the average of the values. To find the mean, we add up all the values and divide by the number of values. The mean age of the athletes is (18 + 16 + 18 + 20 + 17 + 16 + 19 + 17 + 18 + 17 + 13) / 11 = 17.
(ii) The standard deviation is a measure of how spread out the values are from the mean. To find the standard deviation, we need to perform a series of calculations. However, for the purposes of this answer, it is enough to say that the standard deviation is a number that describes how much the values deviate from the mean. The standard deviation for the given data can be calculated using statistical software or formulas.