A cell phone company bills on a monthly basis each bill includes a $45 service fee plus $3.20 in taxes and zero dollars for $.10 for each minute over the given 500 minutes per month Write an expression to describe the cost of the cell phone service per month where X represents a number of minutes over 500
If a company raises the service fee how will expression change?
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Arandom sample of n = 25 observations is taken from a n(µ, σ ) population. a 95% confidence interval for µ was calculated to be (42.16, 57.84). the researcher feels that this interval is too wide. you want to reduce the interval to a width at most 12 units. a) for a confidence level of 95%, calculate the smallest sample size needed. b) for a sample size fixed at n = 25, calculate the largest confidence level 100(1 − α)% needed.