Respuesta :
Answer:
Option a) 1.6 .
Step-by-step explanation:
We are given that 142 subjects were treated with acupuncture. The numbers of migraine attacks for the treatment group had a mean of 1.8 and a standard deviation of 1.4 which means;
Sample Mean, [tex]xbar[/tex] = 1.8 , Sample standard deviation, s = 1.4 and Sample size = 142.
Now, 95% confidence interval estimate of the mean number of migraine attacks for all people treated with acupuncture is given by;
[tex]xbar \pm 1.96 *\frac{s}{\sqrt{n} }[/tex]
⇒ [tex]1.8 \pm 1.96 *\frac{1.4}{\sqrt{142} }[/tex]
So, the lower bound = [tex]1.8 - 1.96 *\frac{1.4}{\sqrt{142} }[/tex] = 1.56 ≈ 1.6
Therefore, option A is correct.
the mean number of migraine attacks for all people treated with acupuncture is 1.6.
- The calculation is as follows:
[tex]= \bar {x} \pm1.96 ]\times\frac{8}{\sqrt{m} } \\\\= 1.8 \pm 1.96 \times \frac{1.4}{\sqrt{142} } \\\\= 1.56[/tex]
= 1.60
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