Ok, let's find the standard deviation of the data set:
Step 1: calculate the mean.
(48+30+24+42+60+24)/6=228/6=38
Step 2: calculate the square of the distance from the mean for each piece of data.
|48-38|²=10²=100
|30-38|²=8²=64
|24-38|²=14²=196
|42-38|²=4²=16
|60-38|²=22²=484
|24-38|²=14²=196
Step 3: add the values that resulted from step 2.
100+64+196+16+484+196=1056
Step 4: divide by the number of data.
1056/6=176
Step 5: take the square root.
√176≈13.27
Finally we obtain that the standard deviation is 13.27.