Answer:
a) <em>Z-score = 0.75</em>
b) <em>Z-score = -32.833</em>
Step-by-step explanation:
<u><em>Step(i):-</em></u>
Given that mean of the Population = 33
Given a standard deviation of the Population = 12
Let 'X' be a random variable in a normal distribution
Let 'X' = 42
<u><em>Step(ii):-</em></u>
<em> </em>
<em></em>
<em> </em>
<em></em>
<u><em>Step(iii):-</em></u>
<em>Given that mean of the Population = 89</em>
Given a standard deviation of the Population = 1
Let 'X' be a random variable in a normal distribution
Let 'X⁻ = 82
<em> </em>
<em></em>
<em> </em>
<em></em>
<em>Z-score = -32.833</em>
<em></em>
Answer:
For the first city, the 95% confidence interval would be:
28,900 +/- 2300 x 3 = 28,900 +/-6900$
For the second city, the 95% confidence interval would be:
30,300 +/- 2100 x 3 = 30,300 +/- 6300$