# statistics

a simple random smaple of 55 mathematics teachers were timed as they completed sudoku puzzles. Their mean completion time was 20.3 minutes. The population standard deviation is assumed to be 12 mintues and times vary normally. Find 99% confidence interval for the mean time for completing a sudoku puzzle by a math teacher.

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1. 99% = mean ± 2.575 SEm (Standard Error of the mean)

SEm = SD/√(n-1)

You can do the calculations.

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2. gdbgddg

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