A market research group would like to know the satisfaction of subscribers in terms of the quality of service provided by Smart Communications and Globe Telecom. Using a survey, they gathered data from two independent samples. The data below summarizes the average customer satisfaction score (out of 10) towards the quality of services of their mobile providers. The satisfaction score is assumed to be normally distributed with unknown and UNEQUAL population variances. Statistics Smart Communications Globe Telecom Mean 4.20 3.15 Standard Deviation 1.25 2.25 Sample Size 25 20 a) Is there a difference in the average satisfaction scores of subscribers from Smart Communications and Globe Telecom? Make the comparisons at the 10% and 5% levels of significance. b) On average, are subscribers from Smart Communications more satisfied with their service provider than from the subscribers from Globe Telecom? Use the 5% and 1% levels of significance.

Fuel efficiency of Prius:  Fueleconomy.gov, the official US government source for fuel economy information, allows users to share gas mileage information on their vehicles. The histogram below shows the distribution of gas mileage in miles per gallon (MPG) from 14 users who drive a 2012 Toyota Prius. The sample mean is 53.3 MPG and the standard deviation is 5.2 MPG. Note that these data are user estimates and since the source data cannot be verified, the accuracy of these estimates are not guaranteed. (a) The EPA claims that a 2012 Prius gets 50 MPG (city and highway mileage combined). Do these data provide strong evidence against this estimate for drivers who participate on fueleconomy.gov? The test statistic is: __________________(please round to two decimal places)The p-value:___________________________ for this hypothesis test is:  (please round to four decimal places)(c) Please comment on the primary thing that is wrong about the following statement: There is sufficient evidence…

During a quality assurance check, the actual contents (in grams) of six containers of protein powder were recorded as 1527, 1532, 1504, 1517, 1528, and 1516. (a) Find the mean and the median of the contents. (b) The third value was incorrectly measured and is actually 1520. Find the mean and the median of the contents again. (c) Which measure of central tendency, the mean or the median, was affected more by the data entry error? ..... (a) The mean is (Round to one decimal place as needed.) The median is (Type an integer or a decimal. Do not round.) (b) The mean is (Round to one decimal place as needed.) The median is (Type an integer or a decimal. Do not round.) (c) After correcting the error, the mean by and the median by The was affected more. (Round to one decimal place as needed.)

The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures students' study habits and attitudes toward school. The survey yields several scores, one of which measures student attitudes toward studying. The mean student attitude score for college students is about 30, and standard deviation is about 12. A researcher in the Philippines is concerned about the declining performance of college graduates on professional licensure and board exams. She suspects that poor attitudes of students are partly responsible for the decline and that the mean for college seniors who plan to take professional licensure or board exams is less than 30. She gives the SSHA to an SRS of 144 college seniors in the Philippines who plan to take professional licensure or board exams. Suppose we know that the student attitude scores in the population of such students are Normally distributed with standard deviation σ = 12. (a) We seek evidence against the claim that μ = 30. What is the…

During a quality assurance check, the actual contents (in grams) of six containers of protein powder were recorded as 1524, 1526, 1499, 1512, 1532, and 1514. (a) Find the mean and the median of the contents. (b) The third value was incorrectly measured and is actually 1518. Find the mean and the median of the contents again. (c) Which measure of central tendency, the mean or the median, was affected more by the data entry error? (a) The mean is 1517.8. (Round to one decimal place as needed.) The median is 1519 (Type an integer or a decimal. Do not round.) (b) The mean is 1521 (Round to one decimal place as needed.) The median is 1521 (Type an integer or a decimal. Do not round.) (c) After correcting the error, the mean affected more. (Round to one decimal place as needed.) by and the median by The was