Answer:
B: 4 solutions
Step-by-step explanation:
Combining the two equations results in 2x² = 52, or x² = 26.
This equation has two solutions: x = ±√26.
As before, x² = 26. If we substitute 26 for x² in the 1st equation, we get:
26 - 4y² = 16, or 4y² = 10, or y = ±√5/2. Again: two solutions.
If we take x to be +√26, y could be ±√(5/2).
Check: is ( √26, √(5/2) ) a solution of the system?
Subbing these values into the first equation, we get:
26 - 4(5/2) = 16. Is this true?
Then 10 = 10. Yes.
Through three more checks, we find that this system has FOUR solutions.
11 squared is 121
20 squared is 400
121+400= 521
The approximate square root of 521 is approximately 22.8254
<span>A
−10 + 16 = 6
........................................................</span>
Using the z-distribution, it is found that the 90% confidence interval is given by: (0.6350, 0.6984).
<h3>What is a confidence interval of proportions?</h3>
A confidence interval of proportions is given by:
In which:
is the sample proportion.
In this problem, we have a 90% confidence level, hence
, z is the value of Z that has a p-value of 
, so the critical value is z = 1.645.
The sample size and the estimate are given by:
Hence, the bounds of the interval are given by:
The 90% confidence interval is given by: (0.6350, 0.6984).
More can be learned about the z-distribution at brainly.com/question/25890103
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