Chapter 5.1, Problem 1E

Special Rounding instructions When you perform logistic regression, round the $r$ value to three decimal places and other parameters to two decimal places. Round all answers to two decimals places unless otherwise indicated.

Ebola Figure $5.14$ shows a plot of the total number $E$ of Ebola cases in West Africa reported to the centers for Diseases control and Prevention from April $1$, $2014$, through December $1$, $2015$. A logistic fit for these data is given by,

$E=\frac{27,841.42}{1+134.65e^{-0.646t}}$.

Where $t$ is the time in months since April $1$, $2014$. In figure $5.15$, we have added the graph of this model.

a. Does Figure $5.14$ show a continuing epidemic or a health crisis that is under control by December $2015$?

b. According to the model, what was the total number of cases when the disease was spreading at the fastest rate? Round your answer to the nearest whole number.

c. Use the crossing- graphs method to determine when the disease was growing at the fastest rate. Round your answer, in months, to one decimal place.