The current electric Tesla Model S can travel an average of 300 miles on a single charge, μ equals 300 miles, with a presumed population standard deviation, σ, of 40 miles. You are a researcher for the team that is developing a prototype for the next Tesla Model S. Your objective is to produce a vehicle that will be able to be driven significantly more than 300 miles on a single charge. You have conducted a test of your most promising prototype; 100 test drives were made. Here are the results: ---you can see in image(screenshot) What test statistic should you use? Step 2. Select the Level of Significance, α A 5 percent significance level has been selected.

You are a researcher studying the lifespan of a certain species of bacteria.  A preliminary sample of 35 bacteria reveals a sample mean of ¯x=76x¯=76 hours. The population standard deviation is known to be 5.6  hours.  You would like to estimate the mean lifespan for this species of bacteria to within a margin of error of 0.4 hours at a 90% level of confidence. How many more bacteria should you sample to achieve a 0.4 hour margin of error? n =     bacteria

Question 4 Use the empirical rule to solve the problem. The amount of Jen's monthly phone bill is normally distributed with a mean of $58 and a standard deviation of $12. What percentage of her phonė bills are between $22 and $94? O 99.99% O 99.7% O 68% O 95% « > A Moving to another question will save this response. 4:42 PM rch 3/25/2021 DII FS PrtScn Home F9 End F10 PgUp PgDn F11 F12 F6 F7 F8 4. 5 6 8. 9. E R T Y U D F G H J K L

For a population with a mean of ? = 80 and a standard deviation of ? = 12, a score of X = 77 corresponds to z = −0.50. True or false?

Assume that adults have IQ scores that are normally distributed with a mean of 95.2, and a standard deviation of 22.2 Find the first quartile Q1, which is the IQ score separating the bottom​ 25% from the top​ 75%. Can you please provide step by step using the T1-84 plus calculator.   I keep getting stuck on locating the z-score.  I know the first Q is .25  If you use the formula, please provide the actual figures including a picture- so I have a well-rounded answer to this question.   Thank you

A sample of n = 64 scores has a mean of M = 68. Assuming that the population mean is p = 60, find the z-score for this sample: If it was obtained from a population with o = 16 Z = If it was obtained from a population with o = 32 Z = If it was obtained from a population with o = 48 Z =

Answer A through E

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately o = 23.8. You would like to be 98% confident that your estimate is within 2.5 of the true population mean. How large of a sample size is required? Do not round mid-calculation. However, you are encouraged to use a critical value accurate to three decimal places – this is important for the system to be able to give hints for incorrect answers.

A standardized test is given to a sixth-grade class. Historically the mean score has been 151 with a standard deviation of 21. The superintendent believes that the standard deviation of performance may have recently decreased. She randomly sampled 23 students and found a mean of 161 with a standard deviation of 18.2898. Is there evidence that the standard deviation has decreased at the α=0.05 level? Step 1 of 5 : State of the hypotheses in terms of the standard deviation. Round the standard deviation to four decimal places when necessary Step 2 of 5 : Determine the critical value(s) of the test statistic. If the test is two-tailed, separate the values with a comma. Round your answer to three decimal places. Step 3 of 5 : Determine the value of the test statistic. Round your answer to three decimal places. Step 4 of 5 : Make the decision. Step 5 of 5 : What is the conclusion?

Solve question 9, Part A, Part B and Part C only.