Step 1 :The z-score is a measure of how many standard deviations an element is from the mean. If an element is below the mean, the z-score is negative. If an element is above the mean, the z-score is positive.
Step 2 :In the first question, $x=4$ is 1.3 standard deviations to the left of the mean. This means that the z-score is -1.3.
Step 3 :Final Answer: The z-score of $x=4$ if it is 1.3 standard deviations to the left of the mean is \(\boxed{-1.3}\).