The equation yˆ=−5.131x 2+31.821x−3.333 approximates the number of people standing in line to catch a commuter train x hours after 5 a. m.what is the best estimate for the number of people in line at 7 a. m.? 23 27 32 40

For this case we have the following equation:
 
 When it's 5 a.m. then x = 0
 Therefore, when it is 7 a.m. then x = 2.
 Substituting x = 2 in the equation we have:
 
 Rounding to the nearest whole number:
 
 
 the best estimate for the number of people in line at 7 a.m. is:
 y = 40