To find how many standard deviations a value is from the mean, you can use the formula:
z = (x - mean) / standard deviation
where z is the number of standard deviations from the mean, x is the value, mean is the mean, and standard deviation is the standard deviation.
For the values 45, 78, 62, 90, and 31:
z_1 = (45 - 61.2) / 21.4
z_2 = (78 - 61.2) / 21.4
z_3 = (62 - 61.2) / 21.4
z_4 = (90 - 61.2) / 21.4
z_5 = (31 - 61.2) / 21.4
Calculating these values, we get:
z_1 ≈ -0.756
z_2 ≈ 0.785
z_3 ≈ 0.037
z_4 ≈ 1.344
z_5 ≈ -1.409
So the values 45, 78, 62, 90, and 31 fall within approximately -1.41, -0.76, 0.04, 0.79, and 1.34 standard deviations of the mean, respectively.