MSIT 3000 Lecture Notes - Lecture 2: Confidence Interval, Standard Deviation
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Suppose delta knows that 40% of its customers are travelling because of business. The proportion of all customers who travel for business reasons. Yes p = . 40: what is the standard error? (or, what is the standard deviation of the proportion of customers who are travelling for business reasons?) Apple wants to know what proportion of iphone users also use other apple products. If fewer than 30% of iphone users also use other apple products, apple will invest more in marketing. They randomly select 80 iphone users and ask each individual whether or not they use other. The population of iphone users is at least 10*80 = 800. There are at least 10 failures and 10 successes. The chosen individuals independently own iphones. (the probability that one individual owns an iphone does not affect the probability that another person owns an iphone. : what is the standard error? (. 488(1-. 0488)/80) raised to the = . 056.