Statistics help please.

A standard placement test has a mean of 115 and a standard deviation of ? = 10. Determine the minimum sample size if we want to be 95% certain that we are within 3 points of the true mean.

This isn't anything fancy. Just use the formula \(\displaystyle n=\left(\frac{z\cdot {\sigma}}{E}\right)^{2}\)

Notice where this formula comes from?. It comes from the confidence interval formula solved for n:

\(\displaystyle E=z\cdot\frac{\sigma}{\sqrt{n}}\)

\(\displaystyle E\sqrt{n}=z{\sigma}\)

\(\displaystyle \sqrt{n}=\frac{z\sigma}{E}\)

\(\displaystyle n=\left(\frac{z\sigma}{E}\right)^{2}\)

Plug in your givens remembering that the z score for 95% is 1.96. Round up your solution.

> Your mom is so fat, when she walks she sheds vortices so large that Modern Synoptic Scale models include her as a factor.

Your mom is so fat she has to iron her panties in the driveway.

Your mom is so fat she has to iron her panties in the driveway.

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I put those silly things up there because I thought they were different and off the wall compared to most jokes.

is this a real site .. or its a site for games

melius bd said:

is this a real site .. or its a site for games

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What makes you think that this is a site for games??? What games????