People in the aerospace industry conducted a pilot study to determine the relationship between the weight and cost of a major object being sent into space. The results of the pilot study are in data file SP13.53, contained in a folder under the CML quizzes tab. Determine the number of observations needed to be 89% confident that the estimate of the average weight is within 0.3 units of the overall mean weight. Note: Assume that the pilot study standard deviation is a good estimate of the population standard deviation, that an appropriate value from the Z-table can be used, and that hand calculations are used to find the answer (i.e. do not use Kaddstat). Hint: in Excel, use Data > Data Analysis > Descriptive Statistics, to find the sample standard deviation.