Question 20 2 pts An electric car manufacturer is considering a new source for lithium batteries. The new source is more expensive but their batteries are said to last longer which should result in fewer warranty claims. Suppose that independent random samples of 60 batteries from the current source and 50 batteries from the new source are selected. Let p0 represent the proportion of batteries from their current source that will last longer than 5 years (the current warranty for the car) and PN represent the proportion of batteries from the new source that will last longer than 5 years. What is the mean of the sampling distribution for I30 N? PN(1PN) Question 19 2 pts Joe has a food truck. During the summer, the distribution of his daily sales is approximately normal with a mean of $675 and a standard deviation of $35. Which of the following is the z-score for a sales day of $700? 0 Z700: 'O.7l4 O 2700 = 0.714 O 2700 =1.729 O 2700 = - 0.729 Question 18 2 pts The mean number of AP courses taken in high school for incoming rst-year students at the University of Virginia is 7.6 with a standard deviation of 1.8. A random sample of n=12 students is selected. What is the mean of the sampling distribution of the sample mean for samples of size 12? O 2.19 O 7.6 o 1.8 O 0.52 Question 17 2 pts Approximately 23% of car crashes in the U.S. involve cell phone use. A random sample of n=300 car crash accidents are selected from Virginia (which had over 8 million car crashes last year) and 75 of those in the sample involve cell phone use. Which of the following is closest to the probability that 75 or more crashes would involve cell phone use? 0 0.7947 0 0.50 0 0.2053 0 0.347' Question 16 2 pts The mean SAT score for incoming rst-year students at the University of Virginia is 1340 with a standard deviation of 50 points. A random sample of n=12 students is selected. What is the mean of the sampling distribution of the sample mean for samples of size 12? 050 0 386.82 0 14.43 0 1340 Question 15 2 pts A hairstylist rents space at a local hair salon. A customer can either request a haircut or hair coloring. The hairstylist has determined the number of haircuts each day is a random variable with a mean of 8 and a standard deviation of 2. The number of hair colorings each day is a random variable with a mean of 2 and a standard deviation of 1.5. What is the mean and standard deviation of the total number of services this hairstylist performs each day. 0 Mean number of services = 6 Standard devation = 2.5 0 Mean number of services = 10 Standard devation = 2.5 0 Mean number of services = 6 Standard devation = 3.5 0 Mean number of services = 10 Standard devation = 3.5 Question 14 2 pts 53% of the students at Freeport High School ride the bus to school. 30% of the students at FHS are juniors. 17% of the students are juniors who ride the bus. A student is randomly selected from the school. Let B represent the event that the student rides the bus to school and let J represent the event the student is a junior. Use the Venn diagram below to determine the probability of randomly selecting a student who is a senior and does not ride the bus to school. 0 0.36 o 0.34 O 0.13 o 0.66