One cable company claims that it has excellent customer service. In fact, the company advertises that a technician will arrive within 40 minutes after a service call is placed. One frustrated customer believes this is not accurate, claiming that it takes over 40 minutes for the cable technician to arrive. The customer asks a simple random sample of 25 other cable customers how long it has taken for the cable technician to arrive when they have called for one. The sample mean for this group is 43.6 minutes with a standard deviation of 6.5 minutes. Assume that the population distribution is approximately normal. Test the customer's claim at the 0.05 level of significance. Step 1 of 3: State the null and alternative hypotheses for the test. Fill in the blank below. Ho : μ = 40 Ηa :μ. 40

As the plant operations manager for Oxford Biotech, you are responsible for monitoring the amount of product placed in each carton. To be consistent with package labeling, cartons should contain a mean of 30 grams of product. Thousands of cartons are produced during a shift, and weighing every single carton was determined to be too time-consuming, costly, and inefficient. Instead, a random sample of cartons is selected. Based on your analysis of the sample, you had to decide whether to maintain, alter, or shut down the process.Using the concept of the sampling distribution of the mean, you are able to determine probabilities that such a sample mean could have been randomly selected from a population with mean of 30 grams. Specifically, if a sample size of n = 20 is selected from a population with mean of 30 grams and standard deviation of 0.60, you calculate the probability of selecting a sample with a mean of 29.85 grams or less to be ____.

When an audit must be conducted that involves a tedious examination of a large inventory, the audit may be very costly and time consuming if each item in the inventory must be examined. In such situations, the auditor frequently obtains a random sample of items from the complete inventory and uses the results of an audit of the sampled items to check the validity of the company's financial statement. A large company’s financial statement claims an inventory that averages $600 per item. The following data are the auditor’s assessment of a random sample of 75 items from the company’s inventory. The values resulting from the audit are rounded to the nearest dollar. Estimate the mean value of an item in the inventory using a 95% confidence interval. Is there substantial evidence (a 5 .01) that the mean value of an item in the inventory is less than $600? What is the target population for the above inferences? Would normal distribution–based procedures be appropriate for answering the…

As the plant operations manager for Oxford Biotech, you are responsible for monitoring the amount of product placed in each carton. To be consistent with package labeling, cartons should contain a mean of 368 grams of product. Thousands of cartons are produced during a shift, and weighing every single carton was determined to be too time-consuming, costly, and inefficient. Instead, a random sample of cartons is selected. Based on your analysis of the sample, you had to decide whether to maintain, alter, or shut down the process. Using the concept of the sampling distribution of the mean, you can determine the probability that such a sample mean could have been randomly selected from a population with mean of 368 grams. Specifically, if a sample size of n = 25 is selected from a population with mean of 368 grams and standard deviation of 15, the probability of selecting a sample with a mean of 365 grams or less is Enter your answers using 4 decimal places (Do NOT enter as a percentage).

A recent Gallup Poll interviewed a random sample of 1523 adults. Of these, 868 bought a lottery tickets in the past year. Suppose that in fact (unknown to Gallup) exactly 60% of all adults bought a lottery ticket in the past year. If Gallup took many simple random samples of 1,523 people, the sample proportion who bought a ticket would vary from sample to sample. The sampling distribution would be close to normal with a mean of 0.6 and a standard deviation of___ A)0.4899 B)0.0251 C)0.00016 D)0.0126

One cable company advertises that it has excellent customer service. In fact, the company advertises that a technician will be there within 30 minutes of when a service call is placed.  One frustrated customer believes this is not the truth, claiming that it takes over 30 minutes for the cable repairman to arrive.  The customer asks 15 of his neighbors how long it has taken for the cable repairman to arrive when they have called for him.  The sample mean for this group is 32.2 minutes with a sample standard deviation of 3.6 minutes.  Test the customer’s claim at the 0.02 level of significance.    (a)  State the null and alternative hypotheses       (b)  Find the value of your test statistic.  Draw a picture and label its location on the normal curve.  Also shade the area where you will find the p-value.          (c)  Calculate the p-value from the sample data.  Compare it to the significance level.  Label it’s value and location on your bell curve           (d)  Write a full…

The State Transportation Department is thinking of changing its speed limit signs. It is considering two new options in addition to the existing sign design. At question is whether the three sign designs will produce the same mean speed. To test this, the department has conducted a limited test in which a stretch of roadway was selected. With the original signs up, a random sample of 30 cars was selected and the speeds were measured. Then, on different days, the two new designs were installed, 30 cars each day were sampled, and their speeds were recorded. Suppose that the following summary statistics were computed based on the data. X₁ = 62.1 X₂ = 58.94 X3 = 71.2 SST = 6016 Based on these sample results and significance level equal to 0.05, what is the sum of squares between?

A statistics content developer at Aplia wanted to know whether study skills are related to memory quality. She invited student volunteers to perform an online memory task. The students saw a list of 60 words and were then asked to recognize a list of 10 words that were on the original list. Students were also asked to provide their GPAs.   Consider the following data set, which was collected from student volunteers in 2009. The table gives the frequency for five intervals of scores on the number of correctly identified words. Use the dropdown menus to complete the table by filling in the missing values for the proportions and percentages. Score Interval f Proportion Percentage 9–10 29 0.19 19% 7–8 53           5–6 50           3–4 22 0.14 14% 1–2 1 0.01 1%

A real-estate appraiser wants to verify the market value for homes on the east side of the city that are very similar to size and style. The appraiser wants to test the popular belief that the average sales price is $37.80 per square foot for such homes. Suppose that a random sample of six sales were selected. The sampled sales prices per square foot are $35.00, $38.10, $37.20, $29.80, $30.30, and $35.40. Assuming a normal distribution is a good model for sales, test the claim that the mean sales price per square foot differs from $37.80 at the 1% significance level.

The National Football League (NFL) records a variety of performance data for individuals and teams. To investigate the importance of passing on the percentage of games won by a team, the following data show the average number of passing yards per attempt (Yds/Att) and the percentage of games won (WinPct) for a random sample of 10 NFL teams for the 2011 season (NFL website). Team Yds/Att WinPct 5.7 26 Arizona Cardinals Atlanta Falcons Carolina Panthers 7.6 67 7.3 52 6.9 51 Chicago Bears Dallas Cowboys 5.1 17 8.6 82 New England Patriots Philadelphia Eagles Seattle Seahawks 5.3 21 6.6 41 St. Louis Rams 6.5 41 Tampa Bay Buccaneers. 6.1 38 a. Choose the correct a scatter diagram with the number of passing yards per attempt on the horizontal axis and the percentage of games won on the vertical axis. B. A. WinPct WinPct 80 DD J F1 70- 60- 50+ -40- 30 20- F2 80 F3 000 000 F4 F5 80- -70 60- 50- 40- 30- 20- S F6 ● - F7 DII F8 F9 F10 () F11 <))) F12 A