Janet correctly answers 45 questions on her science test. There are 50 questions on the test. What percentage did she answer cor
2 answers:
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Answer:
1,496 new car buyers
Step-by-step explanation:
The sample size n in Simple Random Sampling is given by
where
z = 1.645 is the critical value for a 90% confidence level (*)
p= 0.33 is the population proportion.
e = 0.02 is the margin of error
so
<em>(*)</em><em>This is a point z such that the area under the Normal curve N(0,1) inside the interval [-z, z] equals 90% = 0.9</em>
It can be obtained in Excel or OpenOffice Calc with
<em>NORMSINV(0.95)</em>
Given:
The system of inequalities is
To find:
The values of a for which the system has no solution.
Solution:
We have,
...(1)
It means the value of x is less than or equal to 5.
...(2)
It means the value of x is greater than or equal to a
Using (1) and (2), we get
But if a is great than 5, then there is no value of which satisfies this inequality.
Therefore, the system has no solution for a>5.