7. A tennis racket company is testing the rackets. A Wimbledon champion requested an informatic platinum G-6 racket. The champion needs a racket which gives 85 mps first serve speed, which means 180 yards of the court. The company tested this racket using a ground launch system which measures distances at a given speed, and they gathered the following data on 6 runs: 180, 175, 195, 188, 180, 175 At the 5% significance level, determine if this champion will be satisfied with the tennis racket. Perform a critical value test. Assume assumptions are satisfied. 8. A random sample of 28 students' final exam scores in Statistics I, revealed a mean of 63.39 with a standard deviation of 25.17. It is assumed that the grades follow a normal distribution. The teacher believes that on the average his students' final exams are lower than C (70%). Test the hypothesis at the 5% significance level. Perform a p-value test. 9. According to Communications Industry Forecast and Reports, the average person spent 5 hours a day on internet in 2019. In 2020, a random sample of 20 people gave the following number of hours spent on internet: 9.1 4.6 5.4 3.7 5.2 1.7 6.1 1.9 7.6 6.9 6.1 5.5 9 3.9 2.5 2.4 4.7 4.1 3.7 At the 10% significance level, do the data provide sufficient evidence to conclude that the amount of television watched per day has changed? Perform a p-value test. 10. It is believed that the levels of sulfate residuals obtained from photosynthesis of carbon-based substrates are less than 900 grams. To make sure, the scientists in Fiji Islands took a random sample of 15 substrates and the following data was collected. The following data represent the levels of sulfate residuals obtained from photosynthesis of carbon-based substrate, measured in grams: 800, 633, 943, 847, 934, 841, 999, 1021, 342, 540, 550, 872, 809, 990, 1050 From previous studies, it is known that the population has approximately normal distribution. Test the appropriate hypothesis at the 5% significance level. Perform a critical value test. 1 1. A concerned professor wants to find out if his college students sleep less than 8 hour a day. He collected the following data from his evening statistics class: 8, 10, 4, 6, 8, 3, 8, 6, 10, 3, 5, 5, 7, 8, 4 Test the hypothesis at the 5% significance. Perform a p-value test