Answer:
I cannot see the graphs, but option D is most likely.
Answer:
Area=Length+height +breath
8cm+7cm+3cm+3cm
Area=21cm
This is an expression equivalent to the problem (f g) (10)
The question is incomplete! Complete question along with answer and step by step explanation is provided below.
Question:
The lifetime (in hours) of a 60-watt light bulb is a random variable that has a Normal distribution with σ = 30 hours. A random sample of 25 bulbs put on test produced a sample mean lifetime of = 1038 hours.
If in the study of the lifetime of 60-watt light bulbs it was desired to have a margin of error no larger than 6 hours with 99% confidence, how many randomly selected 60-watt light bulbs should be tested to achieve this result?
Given Information:
standard deviation = σ = 30 hours
confidence level = 99%
Margin of error = 6 hours
Required Information:
sample size = n = ?
Answer:
sample size = n ≈ 165
Step-by-step explanation:
We know that margin of error is given by
Margin of error = z*(σ/√n)
Where z is the corresponding confidence level score, σ is the standard deviation and n is the sample size
√n = z*σ/Margin of error
squaring both sides
n = (z*σ/Margin of error)²
For 99% confidence level the z-score is 2.576
n = (2.576*30/6)²
n = 164.73
since number of bulbs cannot be in fraction so rounding off yields
n ≈ 165
Therefore, a sample size of 165 bulbs is needed to ensure a margin of error not greater than 6 hours.
Answer: [A]: "library card".
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Explanation: One would need a valid, government-issued photo ID card (i.e. that has not expires).
Although SOME library cards include one's picture, library cards do not constitute "valid ID's" because they are not "government-issued" and would, theoretically, be easy to be made fraudulently (e.g. not have security-issued seals and features).
Even "school ID's"; or "college ID cards"; even if "current" (e.g. currently enrolled" with a photo ID) would not be considered "official" and would only be considered "secondary ID".
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