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There is no math for meaningfully aggregating percentiles. Once you've summarized things as percentiles (and discarded the raw data or histogram distribution behind them) there is no way to aggregate the summarized percentiles into anything useful for the same percentile levels. And yes, this means that those "average percentile" legend numbers that show in ...


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Hint. Currently, the worker being considered makes $\$16$ and is told that only $5\%$ make more. Hence this person is in the $95$th percentile. In other words, his/her z-score is $1.644854$.


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Let $X$ be the number of years to the next earthquake. Then $X$ is a geometric random variable and the probability that the next earthquake happens in $k$ years is $P(X = k) = (1-p)^k \cdot p$ where $p = 0.04$. The expected value of $X$ is $E(X) = 1/p = 1/0.04 = 25 \:\text{years.}$ And this can also be interpreted as if you waited a long period of ...


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Suppose the probability that an earthquake occurs is p in one year. We assume that the probability of an earthquake is independent from the number of eqrthquake in the past. Therefore the probability that you do not occour an earthquake in n years is $(1-p)^n$. Now can consider smaller intervals than one year like half a year. We assume that the occurence ...


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I will show two calcultions. Example: w = (4.52 ± 0.02) cm, x = ( 2.0 ± 0.2) cm, y = (3.0 ± 0.6) cm. Find z = x + y - w and its uncertainty. z = x + y - w = 2.0 + 3.0 - 4.5 = 0.5 cm METHOD 1 Delta z = Delta x + Delta y + Delta w = 0.2 + 0.6 + 0.02 = 0.82 rounding to 0.8 cm So z = (0.5 ± 0.8) cm METHOD 2 Solution with standard deviations Delta z ...



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