In a survey, 291 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $30.78 and standard deviation of $6.09. Estimate how much a typical parent would spend on their child's birthday gift (use a z-interval at a 80% confidence level). Give your answers to 2 decimal places. Express your answer in the format of E.

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A simple random sample of size n is drawn. The sample mean, x, is found to be 18.2, and the sample standard deviation, s, is found to be 4.6. Click the icon to view the table of areas under the t-distribution. (C) COnsLi uci a 9970 CONmueICe Ntervai aboul p || he sampie Size, II, IS 34. Lower bound: 16.04 ; Upper bound: 20.36 (Use ascending order. Round to two decimal places as needed.) Compare the results to those obtained in part (a). How does increasing the level of confidence affect the size of the margin of error, E? A. The margin of error decreases. B. The margin of error increases. C. The margin of error does not change. (d) If the sample size is 17, what conditions must be satisfied to compute the confidence interval? A. The sample size must be large and the sample should not have any outliers. B. The sample data must come from a population that is normally distributed with no outliers. C. The sample must come from a population that is normally distributed and the sample size…

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