Homework SourseThe time in seconds it takes 20 individual sewing machines t
The time in seconds it takes 20 individual sewing machines to stich a border onto a particular garment is listed below.
67 69 64 71 73
58 71 64 62 67
62 57 67 60 65
60 63 72 56 64
Calculate the mean stitching time and the standard deviation to the nearest hundredth of a second.
Solution
To find standard deviation we use the following formula
=(xiX¯¯¯)^2/n1
We will compute this formula in 4 steps.
Step 1: Find the mean. (X¯¯¯)
In this example: X¯¯¯=64.6. (use this calculator for step by step explanation on how to find mean).
Step 2: Create the following table.
Step 3: Find the sum of numbers in the last column to get.
(xiX¯¯¯)2=478.8
Step 4: Calculata using the above formula.
=(xiX¯¯¯)^2/n1 =sqrt root(478.8/(201))=5.02
| data | data-mean | (data - mean)2 |
| 67 | 2.4 | 5.76 |
| 69 | 4.4 | 19.36 |
| 64 | -0.6 | 0.36 |
| 71 | 6.4 | 40.96 |
| 73 | 8.4 | 70.56 |
| 58 | -6.6 | 43.56 |
| 71 | 6.4 | 40.96 |
| 64 | -0.6 | 0.36 |
| 62 | -2.6 | 6.76 |
| 67 | 2.4 | 5.76 |
| 62 | -2.6 | 6.76 |
| 57 | -7.6 | 57.76 |
| 67 | 2.4 | 5.76 |
| 60 | -4.6 | 21.16 |
| 65 | 0.4 | 0.16 |
| 60 | -4.6 | 21.16 |
| 63 | -1.6 | 2.56 |
| 72 | 7.4 | 54.76 |
| 56 | -8.6 | 73.96 |
| 64 | -0.6 | 0.36 |
