Respuesta :
Answer:
The margin of error is of 0.7123 hours.
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1-0.9}{2} = 0.05[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1-\alpha[/tex].
So it is z with a pvalue of [tex]1-0.05 = 0.95[/tex], so [tex]z = 1.645[/tex]
Now, find the margin of error M as such
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
Find the margin of error for a confidence interval for the population mean with a 90% confidence level.
We have that [tex]\sigma = 1.5, n = 12[/tex]. So
[tex]M = 1.645*\frac{1.5}{\sqrt{12}} = 0.7123[/tex]
The margin of error is of 0.7123 hours.
Answer:
0.526
Step-by-step explanation:
To find the margin of error we need to identify three things: the z-score, σ, and n.
1.Find zα2 using invNorm. The invNormfunction has one input: probability.
Here, α=1−0.90=0.10. Probability is then 1−0.102=0.95. To find our z-score, we select invNorm after pressing 2nd then VARS. Type invNorm(0.95). The output Is 1.6448. This is the z-score.
2. σ=1.5.
3. n=22.
4. We type 1.6448×1.522√ on the calculator. The output is 0.526, when rounded to three decimal places. This is the margin of error.
