SOLUTION: Jamey wanted to understand whether students at her school were in favor of an extended school day. She surveyed some students and displayed the results in the table below:
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-> SOLUTION: Jamey wanted to understand whether students at her school were in favor of an extended school day. She surveyed some students and displayed the results in the table below:
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Question 1012311: Jamey wanted to understand whether students at her school were in favor of an extended school day. She surveyed some students and displayed the results in the table below:
If the principal randomly selects a student in grade 9 from this survey, what is the probability that the student is in favor of extending the school day? Answer by jim_thompson5910(35256) (Show Source):
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Let's add on the totals (row totals and column totals). These values represent the sum along the rows or columns.
In Favor
Opposed
Undecided
Total
Grade 9
5
3
9
17
Grade 10
8
12
9
29
Grade 11
15
16
10
41
Grade 12
12
6
11
29
Total
40
37
39
116
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"If the principal randomly selects a student in grade 9 from this survey"
So we're just focusing on the "grade 9" row. There are 17 students in this grade. There are 5 who are in favor, so
P(In favor | grade 9) = (# who are in grade 9 AND in favor)/(# who are in grade 9)
As a fraction, the probability is 5/17
As a decimal, the probability is approximately 0.2941176 (used a calculator)
As a percentage, the probability is approximately 29.41176%
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