Is this a function or not?
2 answers:
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Answer:
a) The point estimate of the proportion of items returned for the population of
sales transactions at the Houston store = 12/80 = 0.15
b) The 95% confidence interval for the proportion of returns at the Houston store = [0.0718 < p < 0.2282].
c) Yes.
We set an hypothesis and construct a test statistics. The test statistics result gives us:
Z calculated = 2.2545, and this gives us the p-value = 0.0121. We assumed 95% confident interval. Hence, the level of significance (α) = 5%. Conclusively, since the p-value ==> 0.0121 is less than (α) = 5%, the test is significant. Hence, the proportion of returns at the Houston store is significantly different from the returns for the nation as a whole.
Step-by-step explanation:
a) Point estimate of the proportion = number of returned items/ total items sold = 12/80 = 0.15.
b) By formula of confident interval:
CI(95%) = p ± Z*,
CI(95%) = [0.0718 < p < 0.2282]
c) The hypothesis:
: The proportion of returns at the Houston store is not significantly different from the returns for the nation as a whole.
: The proportion of returns at the Houston store is significantly different from the returns for the nation as a whole.
The test statistics:
Z = , where
is the proportion of nation returns.
Z calculated = 2.2545, and this gives us the p-value = 0.0121. We assumed 95% confident interval. Hence, the level of significance (α) = 5%. Conclusively, since the p-value ==> 0.0121 is less than (α) = 5%, the test is significant. Hence, the proportion of returns at the Houston store is significantly different from the returns for the nation as a whole.
<h3>Answer: -2w^2 + 25w = 25 or -2w^2 + 25w - 25 = 0</h3>
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Explanation:
Refer to the diagram below. The width is w. We have two opposite and parallel sides equal to this. The other two parallel congruent sides are L = 25-2w meters long. We start with the total amount of fencing, and then subtract off the two width values, so 25-w-w = 25-2w.
The area of the rectangle is
Area = length*width
Area = L*W
Area = (25-2w)*w
Area = 25w - 2w^2
Area = -2w^2 + 25w
Set this equal to the desired area (25 square meters) to get
-2w^2 + 25w = 25
and we can subtract 25 from both sides to get everything on one side
-2w^2 + 25w - 25 = 0
side note: The two approximate solutions of this equation are w = 1.0961 and w = 11.4039 (use the quadratic formula or a graphing calculator to find this)