Suppose that the miles-per-gallon (mp) rating of passenger cars is normally distributed with a mean and...
Suppose that the miles-per-gallon (mpg) rating of passenger cars is normally distributed with a mean and a standard deviation of 39.3 and 2.9 mpg, respectively. [You may find it useful to reference the z table.] a. What is the probability that a randomly selected passenger car gets more than 40 mpg? (Round “z” value to 2 decimal places, and final answer to 4 decimal places.) Probability:________________ b. What is the probability that the average mpg of four randomly selected passenger...
Suppose that the miles-per-gallon (mpg) rating of passenger cars is normally distributed with a mean and a standard deviation of 35.7 and 4.9 mpg, respectively. [You may find it useful to reference the z table.] a. What is the probability that a randomly selected passenger car gets more than 36 mpg? (Round “z” value to 2 decimal places, and final answer to 4 decimal places.) b. What is the probability that the average mpg of four randomly selected passenger cars...
Ch 7 # 5: Please help answer the probability for a-e: A small hair salon in Denver, Colorado, averages about 60 customers on weekdays with a standard deviation of 15. It is safe to assume that the underlying distribution is normal. In an attempt to increase the number of weekday customers, the manager offers a $4 discount on 7 consecutive weekdays. She reports that her strategy has worked since the sample mean of customers during this 7 weekday period jumps...
The mean gas mileage for a hybrid car is 57 miles per gallon. Suppose that the gasoline mileage is approximately normally distributed with a standard deviation of 35 miles per on What proportion of lyrics pots ver miles per gallon? (b) What proportion of hybrids gets 53 miles per gallon or less (c) What proportion of hybrids gets between 57 and 61 miles per gallon? What is the probably that a randomly selected Hybrid gets less than 45 miles per...
An automobile manufacturer claims that their car has a 56.7 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the MPG for this car. After testing 14 cars they found a mean MPG of 56.6 with a standard deviation of 1.1. Is there sufficient evidence at the 0.1 level that the cars underperform the manufacturer's MPG rating? Assume the population distribution is approximately normal. Step 1 of 5: State the null and alternative hypotheses. Answer 2 Points...
The combined gas mileage of mid-size cars varies with mean 25 miles per gallon (mpg) and a standard deviation of about 5.3 mpg. A particular rental car agency typically has 88 midsize cars in its lot. Assume the distribution of combined gas mileage of mid-size cars is Normal. Find the probability that the combined gas mileage for a randomly selected car in the lot is higher than 25 mpg. Find the probability that the mean combined gas mileage for all...
An automobile manufacturer claims that its car has a 33.7 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the MPG for this car since it is believed that the car has an incorrect manufacturer's MPG rating. After testing 120 cars, they found a mean MPG of 34.0. Assume the variance is known to be 2.56. A level of significance of 0.02 will be used. Find the value of the test statistic. Round your answer to 2...
A certain model of automobile has its gas mileage (in miles per gallon, or mpg) normally distributed, with a mean of 26 mpg and a standard deviation of 4 mpg. Find the probability that a car selected at random has the following gas mileages. (Round your answers to four decimal places.) (a) less than 20 mpg (b) greater than 28 mpg (c) between 24 and 28 mpg
Suppose that the speed at which cars go on the freeway is normally distributed with mean 73 mph and standard deviation 8 miles per hour. Let X be the speed for a randomly selected car. Round all answers to 4 decimal places where possible. a. What is the distribution of X? X-N b. If one car is randomly chosen, find the probability that it is traveling more than 72 mph. c. If one of the cars is randomly chosen, find...
Suppose that the speed at which cars go on the freeway is normally distributed with mean 68 mph and standard deviation 6 miles per hour. Let X be the speed for a randomly selected car. Round all answers to 4 decimal places where possible. a. What is the distribution of X? X ~ N(_____,______) b. If one car is randomly chosen, find the probability that it is traveling more than 69 mph. ________ c. If one of the cars is...