A leasing firm claims that the mean number of miles driven annually, μ, in its leased cars is less than 12760miles. A random sample of 13 cars leased from this firm had a mean of 11041 annual miles driven. It is known that the population standard deviation of the number of miles driven in cars from this firm is 2660 miles. Assume that the population is normally distributed. Is there support for the firm's claim at the 0.05 level of significance? Perform a one-tailed test. Then fill in the table below. Carry your intermediate computations to at least three decimal places, and round your responses as specified in the table The null hypothesis: H0: __? The alternative hypothesis: H1: __? The type of test statistic: (Choose one)Z,t,Chi square,F             The value of the test statistic: (Round to at least three decimal places.) __? The critical value at the  0.05  level of significance: (Round to at least three decimal places.) __? Can we support the leasing firm's claim that the mean number of miles driven annually is less than 12760 miles? YES or NO?

A manufacturer needs coil springs that can stand a load of at least 20.0 pounds. Among two suppliers, Supplier A can provide coil springs that can stand a load of 24.5 pounds with a standard deviation of 2.1 pounds. Supplier B’s springs can stand a load of 23.3 pounds with a standard deviation of 1.6 pounds. Assuming normal distributions, determine which of the two suppliers can provide the manufacturer with the smallest percentage of unsatisfactory springs.

The manager of a computer retail store is concerned that his suppliers have been giving him laptop computers with lower than average quality. His research shows that replacement times for the model laptop of concern are normally distributed with a mean of 3.9 years and a standard deviation of 0.6 years. He then randomly selects records on 47 laptops sold in the past and finds that the mean replacement time is 3.7 years. Assuming that the laptop replacement times have a mean of 3.9 years and a standard deviation of 0.6 years, find the probability that 47 randomly selected laptops will have a mean replacement time of 3.7 years or less. P(M≤ 3.7 years) - Enter your answer rounded to 4 decimal places.

A research firm supplies manufacturers with estimates of the sales of their products from samples of stores. Marketing managers often look at the sales estimates and ignore sampling error. An SRS of 50 stores this month shows mean sales of 41 units of a particular appliance with standard deviation of 11 units. During the same month last year, an SRS of 52 stores gave mean sales of 38 units of the same appliance with a standard deviation of 13units. An increase from 38to 41 is a rise of 7.9%.. The marketing manager is happy because sales are up 7.9%.     (a) Give a 95%confidence interval for the difference in mean number of units of the appliance sold at all retail stores. Give your answers to three decimal places. lower bound:     upper bound:

A laboratory claims that the mean sodium level of a healthy adult male is 142 mEq per liter of blood. To test this claim, a random sample of 26 adultspatients is evaluated. The mean sodium level for the sample is 136 mEq per liter of blood. It is known that the population standard deviation of adult sodium levels is 11 mEq. Assume that the population is normally distributed. Can we conclude at the 0.01 level of significance that three population mean adult sodium level differs from that claimed by the laboratory?  Perform a two tailed test, then complete the parts below.

A fast-food franchise, looking to reduce wait times for customers, launched a pilot program where customers could use a smartphone app to place orders. The mean wait times (in seconds) for in-store and drive-through customers at 10 stores participating in the pilot program and at 10 stores not in the program are recorded. Assume that the population standard deviation of mean wait times is 30 seconds for both groups of stores and that the mean wait times are normally distributed for both groups of stores. Let the mean wait times of the stores not in the program be the first sample, and let the mean wait times of the stores in the program be the second sample. The franchise conducts a two-mean hypothesis test at the 0.05 level of significance, to test if there is evidence that the smartphone app reduces wait times. (a) H0:μ1=μ2; Ha:μ1>μ2, which is a right-tailed test. Mean Wait Time: Not In Program Mean Wait Time: In Program 275 176 284 218 307 261 290 252 351 238…

The average undergraduate cost for tuition, fees, and room and board for two-year institutions last year was $14,124. The following year, a random sample of 20 two-year institutions had a mean of $17,124 and a standard deviation of $3700. Is there sufficient evidence at the alpha level of 0.05 to conclude that the mean cost has increased.  Show 6 steps of hypothesis

During the busy season, it is important for the shipping manager at ShipMundo to be able to estimate the time it takes the loading crew to load a truck. The shipping manager has found that she can model the load times using a normal distribution with a mean of 152 minutes and a standard deviation of 15 minutes. Use this table or the ALEKS calculator to find the percentage of load times between 116 minutes and 149 minutes according to the model. For your intermediate computations, use four or more decimal places. Give your final answer to two decimal places (for example 98.23%).

The breaking strengths of cables produced by a certain manufacturer have historically had a mean of 1825 pounds and a standard deviation of 70 pounds. The company believes that, due to an improvement in the manufacturing process, the mean breaking strength, μ, of the cables is now greater than 1825 pounds. To see if this is the case, 17 newly manufactured cables are randomly chosen and tested, and their mean breaking strength is found to be 1844 pounds. Assume that the population is normally distributed. Can we support, at the 0.05 level of significance, the claim that the population mean breaking strength of the newly-manufactured cables is greater than 1825 pounds? Assume that the population standard deviation has not changed. Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas.) (a) State the null hypothesis H0…