Unformatted text preview: randomly selected guy is over 72 inches. 1. Ux=U Ux Is the mean of x_ U is the mean of the population 2. Ox=O/SQRT of N Ox is the st dev of X_ O is the std dev of the population N is the sample size. 1. The pop. Number {annual salaries of all plumbers} 2. The mean of the population is M=46,700 3. The std dev og the population is 5600 4. The sample size n=42>30 5. The samples mean is X_ is a normal RV (according to the central limit theorem) P(X_<44,00) =P(X_Ux/Ox_<44,000Ux_/Ox_) P(Z<44,000U/O/swrt N) P(Z<44,00046,700/(5600/sqrt 42) P(Z<2700/(5600/0.481) P(Z<2700/864.1) P(Z<3.123.12=3.10.02 0.0009 probability (0.09%) that the means salary of the 42 person sample lies below 44,000 1. The population=all gas prices in cali during the week pop mean, u=3.305 pop std dev...
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 Fall '10
 Zhang
 Business, Normal Distribution, Standard Deviation, Variance, randomly selected guy

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