A random sample of 30 commercials made since the year 2010 has an average of 25.1 seconds with a standard deviation of 7.3 seconds. What is the margin of error that corresponds to a 90% confidence interval for the average length of all commercials made since 2010? 2.264 2.192 2.262 2.26 None of the above The correct interpretation of the confidence interval is that we are 90% confident that the interval contains the       length of commercials made since the year 2010. A similar study was conducted and found an interval of (20.5, 28.3). Can we claim the average length of all commercials made since 2010 is at least 20.4? Yes No Not enough information to determine this Beyond representative sampling, what assumptions are needed to satisfy the requirements for this problem? X∼normal or n≥30 X∼binomial, np≥5 and nq≥5 X∼normal and n≥30 X∼binomial and at least 5 successes and failures

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