the mean of normally distributed test scores is 76 and the standard deviation is 3. if there are 170 test scores in the data sample, how many of them were in the 67 to 70 range?

The 67 - 70 range is 3 standard deviations from the mean

2.1% of the scores will fall into this range

So

.021 * 170 = 3.57 ≈ 4 scores will fall into this range