Assume that the standard deviation of the amount of copper precipitate from a
chemical experiment is 4 grams. Approximately how many times should the experiment
be conducted if one wants to be 99% confident that the sample mean amount of precipitate
will be within (+/-)1.288 grams of the unknown population mean amount of precipitate?
A) 30 B) 40 C) 50 D) 64 E) 100 F) 1068
.
Note: If Z ~ N(0,1), then P(Z > 1.96) = 0.025, P(Z > 2.576) = 0.005.
chemical experiment is 4 grams. Approximately how many times should the experiment
be conducted if one wants to be 99% confident that the sample mean amount of precipitate
will be within (+/-)1.288 grams of the unknown population mean amount of precipitate?
A) 30 B) 40 C) 50 D) 64 E) 100 F) 1068
.
Note: If Z ~ N(0,1), then P(Z > 1.96) = 0.025, P(Z > 2.576) = 0.005.
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The margin of error is 1.288 grams. We want to be 99% confident that the population mean is within our estimate (including the margin of error).
The margin of error will be 2.576 * standard error.
2.576 * (4/√n) = 1.288
2.576 * (4/1.288) = √n
n = (2.576 * (4/1.288))² = 64 samples.
The margin of error will be 2.576 * standard error.
2.576 * (4/√n) = 1.288
2.576 * (4/1.288) = √n
n = (2.576 * (4/1.288))² = 64 samples.