The formula log(w) = -2.866 + 2.722log(h) estimates the "average" weight w in pounds of a girl h inches tall. To the nearest tenth of a pound, estimate the "average" weight of a girl who is 47 inches tall.
Do you have a calculator? I assume that the log you are talking about is base 10.
log(47) = 1.672
log(w) = -2.866 + (2.722)(1.672) = 1.6855
w = 10^1.6855 = 48.5 lb
This subject is not trigonometry. It is logarithms. You need a scientific/math hand calculator or a computer to do it. In my school days, we used log tables or a slide rule.
What is Trigonometry?
48.5
To estimate the average weight of a girl who is 47 inches tall using the given formula, we can substitute the value of h = 47 into the equation:
log(w) = -2.866 + 2.722log(h)
First, we need to find the logarithm of 47:
log(47) ≈ 1.67
Now we substitute this value back into the equation:
log(w) = -2.866 + 2.722(1.67)
Using a calculator, we evaluate this expression:
log(w) ≈ -2.866 + 4.554
log(w) ≈ 1.688
To find the weight (w), we need to take the inverse logarithm (or anti-log) of 1.688:
w ≈ 10^1.688
Using a calculator, we evaluate this:
w ≈ 49.87
Therefore, to the nearest tenth of a pound, the estimated average weight of a girl who is 47 inches tall is approximately 49.9 pounds.