Question 1
Paper 1Medium14 marksAn engineer records the water height, cm, in a reservoir while a pump fills it. The pump remains on throughout a planned 8-minute run, and there is no outlet. The measurements shown in Figure 1 were taken during the first 5 minutes. Heights are recorded to the nearest cm.
Using the shape of the data in Figure 1, choose a linear or quadratic model for in terms of Justify your choice.
Let Using the measurements at and show that a fitted model is
Hence, using this model, determine the first time during the 5-minute measurement interval at which the model predicts cm. Give your answer to the nearest minute.
At compare the model’s predicted height with the recorded height. State what this comparison suggests about the model’s fit at that time.
Use the fitted model to predict the height after 8 minutes. State whether this prediction should be considered reliable, giving two reasons.