91影视

Four z-scores corresponding to the test score obtained in a statistics test are given as -2.00, -1.00, 0, 1.00, and 2.00.

Az-score gives an overall idea of how many standard deviations a given observation is above or below the mean value.

In the case of a sample, a z-score is obtained as:

$z=\frac{x-\stackrel{炉}{x}}{s}$

Here,

x is any data value.

$\stackrel{炉}{x}$ is the sample mean.

s is the sample standard deviation.

Apositive z-score indicates that the value is above the mean, and anegative value indicates that the data value is below the mean.

Here, a higher positive z-score implies that the test score obtained is significantly above the mean test score.

Since2.00 is the highest positive value among all the four values, a z-score of 2.00 is preferred over the others.