A university is applying classification methods in order to identify alumni who may be interested in donating money. The university has a database of 58,205 alumni profiles containing numerous variables. Of these 58,205 alumni, only 576 have donated in the past. The university has oversampled the data and trained a random forest of 100 classification trees. For a cutoff value of 0.5, the following confusion matrix summarizes the performance of the random forest on a validation set:

Predicted

Actual

Donation

No Donation

Donation

268

20

No Donation

5375

23439

The following table lists some information on individual observations from the validation set:

Observation ID

Actual Class

Probability of Donation

Predicted Class

A

Donation

0.8

Donation

B

No Donation

0.1

No Donation

C

No Donation

0.6

Donation

a. Explain how the probability of Donation was computed for the 3 observations. Why were observations A and C classified as Donation and observation B was classified as No Donation?

b. Compute the values of accuracy, true positive rate (TPR), false positive rate (FPR) and precision. Evaluate the performance of the classifier, particularly comment on the precision measure taking into account the natural occurrence of donors in the data set.

1. revising for conciseness - eliminating flabby expressions,limiting long lead-ins, and dropping unnecessary fillerstime is money in any business environment. people want information communicated quickly and clearly. to make your writing more concise and understandable, avoid flabby expressions, long lead-ins, and unnecessary fillers. your audience will appreciate your brevity.1. if your writing contains a flabby expression like in view of the fact that, replace it with the word because / although / probably .for each of the following two sentences, choose the best revision.2. i am sending you this letter to inform you that we have experienced an unexpected surprise within our expense sheet, but we are positively certain we will solve it.1) we need to inform you that we have experienced an unexpected surprise with our expense sheet, but we are midway to an end result.2) we have identified a problem with our expense sheet, but we will solve it.3) i am sending you this letter to inform you that we have a problem with our expense sheet, but we are positively certain we have a solution.3. it is the user who should contact the center.1) everyone knows that it is the user who should contact the center.2) the user should contact the center.3) if there is a problem, the user should contact the center.read the following passage, and then answer the question.[1] you scheduled seven conference calls for this morning between 10 and 11 a.m. [2] generally, the company limits the number of conference calls to three per hour. [3] i’m letting you know that in the future, we should be more careful about scheduling.4. which revision limits the long lead-in in sentence 3? 1) in the future, we should be more careful about scheduling.2) i’m letting you know so that in the future we are more careful about scheduling calls.3) so that you know in the future, we should be more careful about scheduling.