Question

Women’s records in the women’s 1500-m run. The formula

R =−0.0026? + 4.0807

can be used to predict the world record, in minutes, for the 1500-m run t years after 1900. Determine (in terms of an inequality) those years for which the world record will be less than 3.8 min.

Answer 1

it would help if there wasn't a ? in the equation.

Answer 2

this is what is written in the text book
i'm confused

Answer 3

maybe it wants you to replace ? with the years. So you say R=-0.0026 * x + 4.0807 < 3.8. Solve for x.

Answer 4

i meant to put >2012 and < 2016

Answer 5

i got that from yahoo answers

Answer 6

rofl. the maths question won't be real statistics, and yahoo answers might just be someone making things up. The question is just abouts maths. It wants you to solve the equation by moving the numbers around.

Answer 7

That's not the right answer for these numbers.

Answer 8

ok can you tell me how to start solving this

Answer 9

add and multiply numbers to both sides to get the ? on one side by itself. You can add any number to both sides and it preserves the inequality. If you multiply by a negative sign, then the inequality gets swapped. So if x < y then -1 * x > -1 * y.

Answer 10

still confused

Answer 11

look up "how to solve a linear equation"

Answer 12

ok thanks

Answer 13

actually, look up "how to solve linear inequalities". They are almost the same, but you have to be a bit careful with multiplying each side....

Answer 14

You want to solve -0.0026 * x + 4.0807 < 3.8

x is the solution. It is "years since 1900" and gives the years when the record should be under 3.8 minutes. You'll find x +1900 to be some year in the 2000s.