A movie theater manager wants to determine whether popcorn sales have increased since the theater switched from using "butter-fl
1 answer:
Answer:
The function that would correctly calculate the 90% range of likely sample means is given by:
B. 4,200±CONFIDENCE.T(0.10,140,12)
Step-by-step explanation:
In Microsoft Excel, the syntax
returns the confidence interval for the population mean, using the students T-distribution.
The standard deviation is given as $140 and the sample size is 12.
In constructing the confidence interval we use:
Let us substitute the values to get:
We use the T distribution because is unknown
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Chebyshev's theorem in statistics states that for many probability distributions, no more than 1/k² of measured values will be k standard deviations away from the mean.
Because the area under the probability distribution curve is equal to 1, Chebyshev's theorem means that the shaded area shown in the figure is equal to 1 - 1/k².
When k = 1.75, the shaded area is
1 - 1/1.75² = 0.7635 = 67.35%
Therefore the percent of the area within +/- 1.75 standard deviations from the mean is
67.35/2 = 33.7%, which is at least 33% of the observations.
Answer:
According to the Chebyshev theorem, at least 33% of the observations lie within +/- standard deviations from the mean.
Because the area under the probability distribution curve is equal to 1, Chebyshev's theorem means that the shaded area shown in the figure is equal to 1 - 1/k².
When k = 1.75, the shaded area is
1 - 1/1.75² = 0.7635 = 67.35%
Therefore the percent of the area within +/- 1.75 standard deviations from the mean is
67.35/2 = 33.7%, which is at least 33% of the observations.
Answer:
According to the Chebyshev theorem, at least 33% of the observations lie within +/- standard deviations from the mean.