Final answer:
The z-score cannot be calculated without the actual score of the patient. However, the z-score is normally found by subtracting the mean from the score and dividing by the standard deviation. The empirical rule assists in understanding what proportion of scores fall within certain z-score ranges.
Step-by-step explanation:
To calculate the z-score for a patient when given a mean score of 28 and a standard deviation of 2, we use the formula:
z = (X - mean) / standard deviation
However, in the provided scenario, the score of the patient (X) has not been given, so we cannot directly calculate the z-score. To proceed, we need the patient's actual score.
If we had a score, for example 26, the z-score would be:
z = (26 - 28) / 2 = -1
This means that a score of 26 is 1 standard deviation below the mean. The empirical rule, also known as the 68-95-99.7 rule, tells us that approximately 68 percent of values lie between z-scores of -1 and 1, about 95 percent between -2 and 2, and about 99.7 percent between -3 and 3.