Answer :
To find the mean, add the two data points together and divide by two. The standard deviation is the square root of the average of squared differences from the mean. The coefficient of variation is the standard deviation divided by the mean and is used to compare data set dispersion.
To calculate the mean, standard deviation, and coefficient of variation for the test data (3700 psi, 2920 psi), follow these steps:
1. First, calculate the mean (average) of the two data points: (3700 + 2920) / 2 = 3310 psi.
2. Next, find the standard deviation, which is the square root of the variance. The variance is the average of the squared differences from the Mean. For our data, variance = [((3700 - 3310) 2 + (2920 - 3310)2) / (2 - 1)] = 389,800. So, the standard deviation is the square root of 389,800, which is approximately 624.34 psi.
3. Finally, the coefficient of variation (CV) is the standard deviation divided by the mean, expressed as a percentage: CV = (624.34 / 3310) x 100 ≈ 18.85%.
The coefficient of variation is useful for comparing the level of dispersion between different sets of data.