Finding z-scores

Front

What is the formula for finding z-scores?

Back

Front

What does a z-score represent?

Back

A z-score indicates how many standard deviations a data point is from the mean.

Front

If a z-score is equal to zero, what does that imply about the x-value?

Back

The x-value is equal to the mean of the data set.

Front

How do you calculate the z-score for a given value?

Back

Subtract the mean from the value and then divide by the standard deviation.

Front

What is the z-score for a value of 42, given a mean of 40 and a standard deviation of 1.4?

Back

Front

What is the z-score for a home priced at $193,000, with a mean of $200,000 and a standard deviation of $10,000?

Back

Front

What is the z-score for a student who scores 31 on the ACT, with a mean of 21 and a standard deviation of 5?

Back

Front

What does a positive z-score indicate?

Back

The value is above the mean.

Front

What does a negative z-score indicate?

Back

The value is below the mean.

Front

In a normal distribution, what percentage of data falls within one standard deviation of the mean?

Back

Approximately 68%.