Answer:
[tex]z=-1.99<\frac{a-288}{3.7}[/tex]
[tex]z=1.99<\frac{a-288}{3.7}[/tex]
And if we solve for a we got
[tex]a=288 -1.99*3.7=214.4[/tex]
[tex]a=288 +1.99*3.7=295.4[/tex]
And the limits for this case are: (214.4; 295.4)
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the annual precipitation of a population, and for this case we know the distribution for X is given by:
[tex]X \sim N(288,3.7)[/tex]
Where [tex]\mu=288[/tex] and [tex]\sigma=3.7[/tex]
The confidence level is 95.44 and the signficance is [tex] 1-0.9544=0.0456[/tex] and the value of [tex]\alpha/2 =0.0228[/tex]. And the critical value for this case is [tex]z = \pm 1.99[/tex]
Using this condition we can find the limits
[tex]z=-1.99<\frac{a-288}{3.7}[/tex]
[tex]z=1.99<\frac{a-288}{3.7}[/tex]
And if we solve for a we got
[tex]a=288 -1.99*3.7=214.4[/tex]
[tex]a=288 +1.99*3.7=295.4[/tex]
And the limits for this case are: (214.4; 295.4)