It's a basic algebra word problem, but I can't seem to figure out the answer; but here goes:
a. Use the regression line y= -0.356x + 257.44 to predict the world record in the year 2015. [Hint: If x represents years after 1900, what value of x corresponds to the year 2015? The resulting y will be in seconds, and should be converted in minutes and seconds.]
b. According to this formula, when will the record be 3 minutes 30 seconds? [Hint: Set the formula equal to 210 seconds and solve. What year coresponds to this x-value?]
The back of the book states that the answer for a is: "3 minutes and 36.5 seconds", while the answer for b is: "In about 2033".
I can't figure out how to get the answer, so any assistance would be much appreciated!
a. Use the regression line y= -0.356x + 257.44 to predict the world record in the year 2015. [Hint: If x represents years after 1900, what value of x corresponds to the year 2015? The resulting y will be in seconds, and should be converted in minutes and seconds.]
b. According to this formula, when will the record be 3 minutes 30 seconds? [Hint: Set the formula equal to 210 seconds and solve. What year coresponds to this x-value?]
The back of the book states that the answer for a is: "3 minutes and 36.5 seconds", while the answer for b is: "In about 2033".
I can't figure out how to get the answer, so any assistance would be much appreciated!
-
a.
2015-1900=115
y=-0.356*115+257.44=216.5
3 minutes and 36.5 sec
b.
210=-0.356x+257.44
-47.44=-0.356x
x=133.26
1900+133.26=2033.26
march of 2033
2015-1900=115
y=-0.356*115+257.44=216.5
3 minutes and 36.5 sec
b.
210=-0.356x+257.44
-47.44=-0.356x
x=133.26
1900+133.26=2033.26
march of 2033