Find the missing number
1 answer:
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Complete Question:
The mean life of a large shipment of CFLs is equal to 7,500 hours. The population standard deviation is 1,000 hours. A random sample of 64 CFLs indicate a sample life of 7,250 hours.
1. State the Null and Alternative Hypothesis.
2. At the 0.05 level of significance, is there evidence that mean life is different from 7,500 hours.
3. Construct a 95% confidence interval estimate of the population mean life of the CFLs.
4. Compute the p-value and interpret its meaning.
Answer:
-2, (7005, 7450), 0.045
Explanation:
1).
H₀: mean of life shipment is 7500 hours
the hypothesis are outlined as follows
H₀: 7500
H₁: 7500
where, n = 64, x = 7250, 1000 hours
Test statistics:
Our conclusion from the above result is that there is sufficient evidence to say that the mean life is different from 7500 hours
2). 95% confidence Interval for the population mean is
3).
the p-value is given by
The height of the tree, which Pat needs to determine, before cutting it down to be sure that it will not fall on a nearby fence is 111 ft.
<h3>What is right angle triangle property?</h3>In a right angle triangle, the ratio of the opposite side to the base side is equal to the tangent angle between them.
Here, (b) is the opposite side, (a) is the base side.
Pat needs to determine the height of a tree before cutting it down to be sure that it will not fall on a nearby fence.
The angle of elevation of the tree from one position on a flat path from the tree is
From a second position,
Farther along this path it is,
Let the distance between tree and first position is x. Thus, from the trigonometry,
....1
The distance between tree and second position is (x+60) ft. Thus, again from the trigonometry,
......2
Compare the equation 1 and 2,
Put this value in equation 1 as,
Thus, the height of the tree, which Pat needs to determine, before cutting it down to be sure that it will not fall on a nearby fence is 111 ft.
Learn more about the right angle triangle property here;
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