The manager of a computer retails store is concerned that his suppliers have been giving him laptop computers with lower than average quality. His research shows that replacement times for the model laptop of concern are normally distributed with a mean of 4.4 years and a standard deviation of 0.4 years He then randomly selects records on 37 laptops sold in the past. Round the answers of following questions to 4 decimal places. a. What is the distribution of X? X N( 4.4 0.4 b. What is the distribution of ? N( 4.4 c. What is the probability that one randomly selected laptop is replaced more than 4.3 years? d. For 37 laptops, find the probability that the average replacement time is more than 4.3 year. e. For part d), is the assumption of normal necessary? O Yes No

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Types of Bias

Statistics is the study of data collection, organization, analysis, interpretation, and presentation. Statistical bias is a characteristic of a statistical technique or its findings in which the expected value deviates from the actual root quantitative parameter being estimated. According to the actual definition of bias, it refers to the tendency of a statistic to overestimate or underestimate a parameter.