Question

Two owners of a cattle ranch, Jo and Val, want to find the average weight for the ranch's 200 cows. Instead of weighing all of the cows: Jo weighs 25 cows and gets an average weight of 1,350 pounds (stdev 50) Val weighs 100 cows and gets an average weight of 1,420 pounds (stdev 50) What is Jo's margin of error, rounded to the nearest whole number? (The formula is )

Answer 1

Jo Margin of error is 20

Explanation:

The expression for calculating Margin of error is =
`Z_(critical ) *\frac{{Sd} }{√(n) }`

From the given question:

`Z_(critical) = 1.96`

standard deviation sd = 50

sample size = 25

THUS; the Margin of error is :

`1.96*\frac{{50} }{√(25) }`

`1.96*\frac{{50} }{5 }`

`1.96*10}`

`19.6`

≅ 20 (to the nearest whole number)

Hence; Jo Margin of error is 20