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Use matrices to solve this linear system: 5x1 − 2x2 = −30 2x1 − x2 = −13 x1 = x2 =

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Nielsen media research wants to estimate the mean amount of time (in minutes) that full- time college students spend watching television each weekday. find the sample size necessary to estimate the mean with a 15-minute margin of error. assume that a 95% confidence level is desired. also assume that the population standard deviation is known to be 112.2 minutes.