Question 1109047
Several years​ ago, 41​% of parents who had children in grades​ K-12 were 
satisfied with the quality of education the students receive.
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A recent poll were asked 1,105 parents who have children in grades​ K-12 if they were satisfied with the quality of education the students receive. Of the 1,105 ​ 
surveyed, 456 indicated that they were satisfied.
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Construct a 90​% confidence interval to assess whether this represents evidence that​ parents' attitudes toward the quality of education have changed. 
What are the null and alternative​ hypotheses? 
The Answer Is [Upper H 0​: p= 0.41 versus H 1​: p is not equal 0.41] 

How do you find what the lower bound number is and what the upper bound number is if the confidence interval 90​% . (Please show steps , especially if using TI-84 Calculator)
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A 90% CI is centered at p or at u.
Each of the tails is 5%.
The boundary z-value of the left tail is as follows::
(Using TI-84+)
2nd DIST
invNorm(0.05) = -1.645
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Because of symmetry the boundary of the right tail is +1.645
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Now find the corresponding proportion values::
(Using TI-84+)
Lower boundary = 0.41-1.645*sqrt(0.41*0.59/1105) = 0.3857
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The upper bound is = 0.41+1.645*sqrt(0.41*0.59/1105) = 0.4343
​(Round to two decimal places as​ needed.)
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Cheers,
Stan H.
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