A manufacturer must test that his bolts are 4.00 cm long when they come off the assembly line. He must recalibrate his machines if the bolts are too long or too short. After sampling 49 randomly selected bolts off the assembly line, he calculates the sample mean to be 4.18 cm. He knows that the population standard deviation is 0.66 cm. Assuming a level of significance of 0.02, is there sufficient evidence to show that the manufacturer needs to recalibrate the machines? Step 2 of 3: Compute the value of the test statistic. Round your answer to two decimal places.

A manufacturer must test that his bolts are 4.00 cm long when they come off the assembly line. He must recalibrate his machines if the bolts are too long or too short. After sampling 49 randomly selected bolts off the assembly line, he calculates the sample mean to be 3.87 cm. He knows that the population standard deviation is 0.44 cm. Assuming a level of significance of 0.02, is there sufficient evidence to show that the manufacturer needs to recalibrate the machines? Step 3 of 3: Draw a conclusion and interpret the decision. Answer 画 Tables 国 Keypad Keyboard Shortcuts We fail to reject the null hypothesis and conclude that there is sufficient evidence at a 0.02 level of significance that the mean length of the bolts is different from 4.00 cm and the machines need to be recalibrated. We reject the null hypothesis and conclude that there is sufficient evidence at a 0.02 level of significance that the mean length of the bolts is different from 4.00 cm and the machines need to be…

A sample of n=36 scores has a standard error of 3. What is the standard deviation of the population from which the sample is obtained?

A chain of restaurants has historically had a mean wait time of 5 minutes for its customers. Recently, the restaurant added several very popular dishes back to their menu. Due to this, the manager suspects the wait time, μ, has increased. He takes a random sample of 35 customers. The mean wait time for the sample is 5.1 minutes. Assume the population standard deviation for the wait times is known to be 1.1 minutes. Can the manager conclude that the mean wait time is now greater than 5 minutes? Perform a hypothesis test, using the 0.10 level of significance. (a) State the null hypothesis Ho and the alternative hypothesis H₁. Ho: O H₁:0 μ X 0° OO 20ם ローロ OO × 5 (b) Perform a hypothesis test. The test statistic has a normal distribution (so the test is a "Z-test"). Here is some other information to help you with your test. 0.10 is the value that cuts off an area of 0.10 in the right tail. *-μ ⚫ The test statistic has a normal distribution and the value is given by z=- σ √n Standard Normal…

A manufacturer must test that his bolts are 4.00cm long when they come off the assembly line. He must recalibrate his machines if the bolts are too long or too short. After sampling 81 randomly selected bolts off the assembly line, he calculates the sample mean to be 3.67cm. He knows that the population standard deviation is 1.14cm. Assuming a level of significance of 0.02, is there sufficient evidence to show that the manufacturer needs to recalibrate the machines?

A manufacturer must test that his bolts are 4.00cm long when they come off the assembly line. He must recalibrate his machines if the bolts are too long or too short. After sampling 169 randomly selected bolts off the assembly line, he calculates the sample mean to be 4.07cm . He knows that the population standard deviation is 0.45cm . Assuming a level of significance of 0.02 , is there sufficient evidence to show that the manufacturer needs to recalibrate the machines? Step 2 of 3 : Compute the value of the test statistic. Round your answer to two decimal places.

A machine that grinds valves is set to produce valves whose lengths have mean 100 mm and standard deviation 0.1 mm. The machine is moved to a new location. It is thought that the move may have upset the calibration for the mean length, but that it is unlikely to have changed the standard deviation. Let μ represent the mean length of valves produced after the move. To test the calibration, a sample of 100 valves will be ground, their lengths will be measured, and a test will be made of the hypotheses H0 : μ = 100 versus H1 : μ ≠ 100.  a) If the sample mean length is 100.01 mm, will H0 be rejected at the 10% level? b) A critical point is 100.015 mm. What is the level of the test?

According to an article in Good Housekeeping, a 128-lb woman who walks for 30 minutes four times a week at a steady, four-mi/hr pace can lose up to 10 lbs over a span of a year.  Suppose 35 women with weights between 125 and 130lb perform the four walks per week for a year and at the end of the year the average weight loss for the 35 was 9.1 lbs.  If the sample standard deviation is 5, calculate the value of the test statistic and find the p-value of the hypothesis test of Ho:µ =10 vs H1:µ≠10.

A manufacturer must test that his bolts are 4.00 cm long when they come off the assembly line. He must recalibrate his machines if the bolts are too long or too short. After sampling 121 randomly selected bolts off the assembly line, he calculates the sample mean to be 4.21 cm. He knows that the population standard deviation is 0.83 cm. Assuming a level of significance of 0.02, is there sufficient evidence to show that the manufacturer needs to recalibrate the machines? Step 1 of 3: State the null and alternative hypotheses for the test. Fill in the blank below. Ho :D = H₂H 4.00 4.00