Lesson 5 of 11
Total divided by count
Show on a big screenOne number for the whole week. Share the week's total equally between the days. What each day holds is the mean.
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Step 1 of 4
- Seven bars for the week. Values shown above each one.
- All seven add up. Total = 70.
- Seven days in the list. Count = 7.
- Mean = 70 ÷ 7 = 10, ruled across the strip.
The rule
A function is a named set of lines. This function gives back one answer.
The mean is the total divided by the count. Written as a function, it works on any list you hand it. Longer or shorter, the lines do not change.
let total = 0;— the box, outside the loop.total = total + day;— each reading added on.return total / days.length;— divide, then give back the answer. The sign/means divide.
The count comes from .length. Nothing is counted by hand.
Monday to Saturday is six days, total 66. The mean is 66 ÷ 6 = 11. The whole week is seven days, total 70. Its mean is 70 ÷ 7 = 10.
If Tuesday were 45, not 46, the total is 70 − 1 = 69. 7 does not divide 69 evenly. The machine prints 9.857142857142858. It does not round the answer.
Try the lab to finish this lesson.