Simplify 10 in radical sign times 8 in radical sign

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

Charlie tosses five coins.what is the probability that all five coins will land tails up.

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