On a multiple choice test with 17 questions, each question has four possible answers, one of which is correct. For students who

Question

4 years ago

13

guess at all answers, find the mean for the number of correct answers. a. 12.8.b. 8.5.c. 4.3.d. 5.7.

1 answer:

Ira Lisetskai [31] · Answer 1 · 2021-12-03T20:27:21+03:00

<h2>The required "option c) 4.3" is correct.</h2>

Step-by-step explanation:

Given,

Total number of multiple choice questions = 17

To find, the mean for the number of correct answers = ?

Each question has four possible answers.

If guessing at random:

There is only one in four chances.

$\dfrac{1}{4}\times 100$ = 25 % chance of getting a particular question right.

This is the same probability for each of the 17 questions.

If there is a 25 % chance of getting any given question right.

There are 17 questions.

∴ The total number of questions you will expect to get right =

25 % × 17

= $\dfrac{25}{100} \times 17$

= $\dfrac{17}{4}$

= 4.25

≈ 4.3

∴ The mean for the number of correct answers = 4.3

Thus, the required "option c) 4.3" is correct.