Question

Time

(weeks) Lake Depth
(feet)
0 346.0
2 344.8
5 343.0
7 341.8
10 340.0
12 338.8

An environmental agency studying the effects of drought on a lake found that the water level decreased at a constant rate during the first few months of the drought. When the agency began its research, the depth of the lake was 346 feet. The table represents the agency’s susequent observations about the lake's depth.

Which equation represents the depth of the lake, y, based on the number of weeks passed, x?


y = -0.6x + 346



y = -1.2x + 346



y = -0.6x



y = -1.2x

Answer 1

(0,346)(2,344.8)
slope(m) = (y2 - y1) / (x2 - x1)
slope(m) = (344.8 - 346) / (2 - 0)
slope(m) = -1.2/2 = - 0.6

y = mx + b
slope(m) = - 0.6
(0,346)...x = 0 and y = 346
now we sub
346 = - 0.6(0) = b
346 = b

ur equation is : y = - 0.6x + 346