The 18th month he will have to change both,
I hope this helped!
Answer:
Variance = 4.68
Step-by-step explanation:
The formula for the variance is:

Where:

The mean can be calculated as each value multiplied by its probability


Replacing the mean and the summatory of X:

I think it’s 4.308 when u multiply
I am legit doing this in school but I don't know it lol
Answer:
28 minutes spent in washing the dishes.
Step-by-step explanation:
Given the table
Chore time in minutes
Sweeping 42
Dishes ?
Amanda spent a total of 70 minutes competing her chores this week
Total of 70 minutes spent
42 minutes spent in sweeping . to find the number of minutes Amanda spent in washing the dishes , subtract 42 minutes from the total time spent
let x be the number of minutes spent washing the dishes

To solve for x , subtract 42 from both sides

28 minutes spent in washing the dishes.