Answer all the questions with complete solution, graph and answer

I. State the null and the alternative hypotheses of the following statements.

1. A car dealership announces that the mean time for an oil change is less than 15 minutes. 2. A companyr advertises that the mean life of its furnaces is more than 13 years. 3. A consumer analyst reports that the mean life of a certain type of automobile batteryr is not T4 months. 4. A transportation network oompanjr claims that the mean travel time between two destinations is about 16 minutes. 1. The average age of doctors in Las Pinas is 35 years. 2. The proportion of senior male students' height is significantly higher than that of senior female students.1. critical t-value of -2.086 computed t-value of -2.096 2. critical t-value of +1.071 computed t-value of 1.011. Based on the report of the school nurse, the average height of Grade 1 1 students has increased. Five years ago, the average height of Grade 1 1 students was lTcm with standard deviaiion of 38cm. She took a random sample of 150 students and derived the average height of 1E5cm. 2. A manufacturer of tires claim that their tire has a mean life of at least 5D,I[Ilm1s. A random sample of 23 of these tires is tested and the sample mean is 33,lims. Assume that the population standard deviation is 3,DD[Ikms and the lives of the tires are approximatelyr normally distributed. 3. [n the population, the average IQ is 10!}. A team of scientists wants to test a new medication to see if it has either a positive or a negative effect on intelligence, or no effect at all. A sample of 30 participants who have taken the medication has a mean of 141] with a standard deviation of 21]. Did the medication affect intelligence? Alpha-0.05