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Chapter 12: Q. 9 (page 800)

A random sample of 900students at a very large university was asked which social-networking site they used most often during a typical week. Their responses are shown in the table below.

Assuming that gender and preferred networking site are independent, which of the following is the expected count for female and LinkedIn?

a)18.85b)46.11c)87.00d)91.65e)103.35

Short Answer

Expert verified

The answer is optione)103.35

Step by step solution

01

Given Information

We have been given the total number of students at a very large university is900.

We need to find the expected count for females and LinkedIn.

02

Simplification

When the two factors for a two-way table are independent, the expected value formula is just the number of samples times the two probabilities.

P(F)=c2n, P(L)=r3n

mean=n脳P(F)脳P(L)

localid="1650524309687" mean=c2脳r3n

where c2 is column 2 total, r3 is row 3 total, and n is the grand total. This is taken from the table.

Therefore, c2=477, r3=195, n=900.

mean=477脳195900.

On calculating, we get:

mean=103.35

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