Respuesta :
To find the average, you add all of the numbers and divide by the number of numbers (If that makes sense)
We can use variables (x) to solve for the last number.
268+258+271+x/4 = 266
Multiply both sides by 4
268+258+271+x = 266*4
268+258+271+x = 1064
Add the three numbers together
797+x = 1064
Subtract both sides by 797
x = 267
Her fourth pregnancy must last 267 days.
Answer:
267
Step-by-step explanation:
So we want to find the average of 4 numbers:
268, 258, 271, and x
The average of those 4 numbers is represented by the fraction:
[tex]\frac{268+258+271+x}{4}[/tex]
Now we also wanting this average to be equal to 266. We need to find x such that that happens.
So we have the following equation to solve:
[tex]\frac{268+258+271+x}{4}=266[/tex]
Multiply both sides by 4:
[tex]268+258+271+x=4(266)[/tex]
Do any simplifying on both sides:
[tex]797+x=1064[/tex]
Subtract 797 on both sides:
[tex]x=1064-797[/tex]
Simplify:
[tex]x=267[/tex]