(2p+3q=9)(4p+q=13)using ellimination method.
1 answer:
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Answer:
x = ± 2i
Step-by-step explanation:
note that = i
x² = - 12 ( take square root of both sides )
x = ± = ±
= ± 2i
Answer:
We need a sample size of at least 75.
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
So it is z with a pvalue of , so
Now, we find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
The standard deviation is the square root of the variance. So:
With a .95 probability, the sample size that needs to be taken if the desired margin of error is 5 or less is
We need a sample size of at least n, in which n is found when M = 5. So
We need a sample size of at least 75.