Part 1 of Victoria, an accomplished marathon runner, claims that the standard deviation for her time to run a 26.2 mile marathon is less than 17.5 minutes. To test her claim, Victoria looks up 11 of her race times (in minutes): 227.2, 233.3, 259.7, 265.8, 252.1, 228.8, 222.6, 202.9, 214.5, 237.2, 267.7 Perform a hypothesis test using a 9% level of significance to test Victoria's claim. Step 1: State the null and alternative hypotheses. 17.5 Ha:0

Cody took his first physics exam and scored an 80. The population mean for this exam is 70, and the standard deviation is 5. What is the probability of selecting a person with a score greater than Cody’s?

SOLVE AND GRAPH THE FOLLOWING. WRITE COMPLETE AND NEAT SOLUTIONS.

A quiz consists of 40 multiple choice​ questions, each with five possible​ answers, only one of which is correct. If a student guesses on each​ question, what is the mean and standard deviation of the number of correct​ answers? Round to the nearest thousandth.

The NJ Department of Health has reported the average life span of NJ residents is 81 years. If the standard deviation is σ = 4 years, what is the probability of a person living to at least 92 years of age?

To celebrate the end of final exams you and friends head to a favorite downtown restaurant. You find a street parking spot with a maximum of two hours. If you stay longer than two hours, you risk having your car towed away. No one has a watch or cellphone but you remember that the average time you spent at the same restaurant over your previous 16 visits is 1.5 hours, and you estimate the sample standard deviation to be about 20 minutes. You also need to factor in that it takes 8 minutes to walk to the restaurant and 8 minutes to walk back to your car (you are very certain about these two durations). (a) One of your friends is really worried that you won’t get back to the car in time and so the car might be towed away! Does your friend have good reason to be worried? Test at a 5% significance level whether the mean total time will be less than two hours. (b) You decide to leave the car parked at the street spot but it gets towed. What type of error have you committed?

The University of Georgia has several football players participating in the NFL draft this season. A few former coaches are helping the players prepare for the NFL tryout by tracking their practice performance. One coach calculates the athlete's speed in feet per second each round and then finds the mean and standard deviation for all rounds. Since the workout tested at the NFL tryout is the 40 yard dash, the coach decides to convert these speeds to yards per second instead of feet per second, where 1 yard is equal to 3 feet. Which of the following best describes what would happen to the summary statistics for the athletes? (A) The mean would increase, but the standard deviation would remain the same. (B) Both the mean and standard deviation would remain the same. (C) Both the mean and standard deviation would decrease. (D) The mean would decrease, but the standard deviation would remain the same. (E) The mean would decrease, but the standard deviation would increase.

Suppose the null hypothesis is not rejected. State the conclusion based on the results of the test. Six years​ ago, 11.1​% of registered births were to teenage mothers. A sociologist believes that the percentage has decreased since then.

The distances golf balls travel under laboratory testing conditions are normally distributed. The mean is 312 yards. The probability the golf ball travels further than 319 yards is 0.28. Find the probability a randomly selected golf ball travels between 305 yards and 319 yards. Express the answer as a decimal value rounded to the nearest hundredth.