Electric Engineer Co Ltd buys electrical components in batches of 2000. From time to time a batch is randomly selected and, for quality control purposes, all the components are inspected. The data gives the number of defective components found in 90 batches recently bought. 30, 17, 18, 20, 21, 25, 26, 27, 27, 28, 30, 30, 32, 32, 33, 34, 35, 37, 39, 40, 40, 41, 43, 43, 49, 44, 44, 48, 45, 43, 47, 48, 42, 47, 49, 45, 49, 50, 51, 52, 52, 57, 58, 50, 59, 56, 57, 52, 54, 58, 58, 59, 52, 67, 61, 68, 62, 69, 67, 68, 64, 65, 68, 77, 79, 79, 77, 73, 75, 77, 76, 71, 72, 79, 80, 81, 83, 82, 84, 88, 86, 89, 98, 92, 95, 99, 80, 25, 78, 45. (a) Construct a stem and leaf display for the number of defective components. (b) Using the stem and leaf, evaluate the median, lower quartile, upper quartile and the interquartile range of the given distribution. (c) Using graph paper, draw a box and whisker diagram to represent these data and comment on the shape of the distribution. (d) Form a grouped frequency distribution for the number of defective components with classes of equal width of 9 starting with the smallest value. (e) Using the grouped frequency distribution in (d), evaluate an estimate of the mean, variance, standard deviation and the coefficient of variation. (f) Using graph paper, draw a histogram to represent the frequency distribution for the grouped frequency data obtained in (d).

A businesswoman is considering whether to open a coffee shop in a local shopping center. Before making this decision, she wants to know how much money people spend per week at coffee shops in that area. She took a random sample of 26 customers from the area who visit coffee shops and asked them to record the amount of money (in dollars) they would spend during the next week at coffee shops. At the end of the week, she obtained the following data (in dollars) from these 26 customers: 16.69 38.73 15.26 14.38 4.99 63.81 10.25 13.15 32.22 36.06 16.30 65.99 10.21 37.08 3.26 6.83 34.56 6.34 36.42 27.69 38.54 13.17 9.75 9.35 1.13 5.27   Assume that the distribution of weekly expenditures at coffee shops by all customers who visit coffee shops in this area is approximately normal. Round your answers to cents.a. What is the point estimate of the corresponding population mean?x ¯ = $Enter your answer; point estimate b. Make a 90 % confidence interval for the average amount of money…

A statistician for an automotive review magazine wants to determine whether there is a difference in the fuel efficiency of passenger vehicles between model years 2013 and 2018. To do this, he selects random makes and models of passenger vehicles and compares the fuel efficiency in miles per gallon of the 2018 model year and the 2013 model year. Suppose that data were collected for a random sample of 9 passenger vehicles, where each difference is calculated by subtracting the fuel efficiency in miles per gallon of the 2013 model year from the fuel efficiency in miles per gallon of the 2018 model year. Assume that the fuel efficiencies are normally distributed. The test statistic is t≈6.163, α=0.10, the corresponding rejection regions are t<−1.860 and t>1.860, the null hypothesis is H0:μd=0, and the alternative hypothesis is Ha:μd≠0. Which of the following statements are accurate for this hypothesis test in order to evaluate the claim that the true mean difference between the fuel…

3. A sample of job applicants is selected to analyze the number of years of experience the job applicants have. The data set is: {1, 3, 3, 1, 2}. What can you conclude about the sample?