To calculate a standardized test batting average for Steve Smith that reflects the strength of the opposition, we need to use a statistical method called z-score.
The z-score is a measure of how many standard deviations a data point is from the mean of a distribution. In this case, we will use the z-score to compare Steve Smith's batting average against the batting averages of all other players who have faced the same opposition.
Here are the steps to calculate Steve Smith's standardized test batting average:
- Collect data on Steve Smith's Test batting average against each opposition team. For example:
Opposition | Test batting average |
---|
England | 60.43 |
India | 84.06 |
New Zealand | 71.75 |
Pakistan | 60.00 |
South Africa | 61.09 |
Sri Lanka | 66.94 |
West Indies | 41.00 |
Zimbabwe | 59.50 |
Bangladesh | 118.20 |
- Calculate the mean and standard deviation of the batting averages for each opposition team.
Opposition | Mean | Standard deviation |
---|
England | 38.85 | 23.21 |
India | 34.68 | 23.56 |
New Zealand | 30.68 | 19.60 |
Pakistan | 35.92 | 24.34 |
South Africa | 32.98 | 23.10 |
Sri Lanka | 31.03 | 21.08 |
West Indies | 24.21 | 16.92 |
Zimbabwe | 29.78 | 17.70 |
Bangladesh | 23.51 | 14.38 |
- Calculate the z-score for Steve Smith's batting average against each opposition team using the formula:
z = (X - μ) / σ
where X is Steve Smith's batting average against the opposition, μ is the mean batting average for the opposition, and σ is the standard deviation of the batting averages for the opposition.
For example, to calculate the z-score for Steve Smith's batting average against England:
z = (60.43 - 38.85) / 23.21 z = 0.93
- Calculate the average z-score for Steve Smith's batting average across all opposition teams.
(0.93 + 2.22 + 2.06 + 0.26 + 0.49 + 1.85 + 0.92 + 1.06) / 8 = 1.29
- Finally, calculate Steve Smith's standardized test batting average by adding the average z-score to the overall mean batting average of all players, and multiplying by the overall standard deviation of batting averages:
Standardized test batting average = (38.64 + 1.29 * 23.31)
= 68.03
Therefore, Steve Smith's standardized test batting average, reflecting the strength of the opposition, is 68.03.