Sutton M.
asked 06/09/20What tells you that the relation is best fit by a linear model? Use principles about what kinds of functions have consistency in which types of rates of change?
Suppose a set of data about the spread (in hundreds of acres) of a food-borne bacteria (after t weeks) in lettuce has the following percentage rates of change: 0.9%, 1.3%, 1.1%, 1.0%, 1.3%, 1.0%; and the following average rates of change: 2.9, 2.4, 3.7, 3.1, 3.6, 3.2. Based only on the information given, and without doing any calculations, what type of model would you use? Why? (NOTE THAT the information given is not the actual data set. I have calculated the two types of rate of change for you. You should NOT BE CALCULATING ANYTHING!)
1 Expert Answer
Omar L. answered 09/05/20
Experienced Engineer Specializing in Tutoring Math, Science, and Eng
Hi Sutton,
Firstly, I will say I might have misunderstood your intentions with the question, but if it is how I interpreted it, it's a great question.
The rate of change seems to follow a sin^2(x)+1.15 (ish) pattern. The average rate of change looks to me somewhat like the definite integral of this derivative equation (albeit with an outlier), which would be required when calculating the average.
At least, when modeling it, that would be the first pairing I would try (just by inspection).
BR,
Omar
Still looking for help? Get the right answer, fast.
Get a free answer to a quick problem.
Most questions answered within 4 hours.
OR
Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.
Jeremiah T.
Here's a Statistics perspective: I look over the data and make a picture, either a scatterplot or a histogram. If the rates of change do not show any outliers and they stay about the same, as the lettuce data does, I try a linear model or linear regression. Does that make sense? Your data is nearly straight, which is needed for linear regression, but if it's not, we can find ways to make it more straight. So I'd use a linear model, remembering that a straight line can be written y = mx + b. m is the slope, and you can find the slope if you know the correlation, the standard deviation, and the mean.06/10/20