The whole class averaged 12 on their assignments with astandard deviation of 3. If Jade averaged 6, then her z- score was

since 6 is 6 less than the mean, that's -2 std away.

Z = (score-mean)/SD

To find Jade's z-score, we first need to understand what a z-score represents. A z-score measures how many standard deviations away from the mean a specific value is.

In this case, we know that the class average is 12 with a standard deviation of 3. Jade's average is 6. To calculate her z-score, we use the formula:

z = (x - μ) / σ

Where:
- z is the z-score
- x is the value we want to find the z-score for (in this case, Jade's average)
- μ is the mean of the data set (the class average)
- σ is the standard deviation of the data set (3 in this case)

Plugging in the values, we have:

z = (6 - 12) / 3
z = -6 / 3
z = -2

So Jade's z-score is -2.