In a study, 320 full term infants were examined at their 4-month checkups for various development milestones. The baby’s predominant sleep position – either prone (on the stomach) or supine (on the back) or side – was determined. The sample results are below. The researcher reported that infants who slept in the side or supine position were less likely to achieve a given milestone (rolling over) that the infants who slept in the prone position. Test the claim of the researcher at the 1% level.   prone supine or side number of infants 121 199 number that roll over 93 119

According to the U.S. Department of Transportation’s Air Travel Consumer Report, the nation’s 12 largest airlines recorded an on-time arrival percentage of 77.4% in 2001. Of interest is to estimate the mean delay time for the 22.6% of all flights that did not arrive on time during 2013. A simple random sample of 28 late arriving flights was selected, and the mean delay time of this sample of 28 flights was 14.2 minutes, with a sample standard deviation of s= 6.4 minutes. Use this information to calculate and interpret a 98% confidence interval for the mean delay time for all flights that did not arrive on time during 2013.

A credit score is used by credit agencies (such as mortgage companies and banks) to assess the creditworthiness of individuals. Values range from 300 to 850, with a credit score over 700 considered to be a quality credit risk. According to a survey, the mean credit score is 702.4. A credit analyst wondered whether high-income individuals (incomes in excess of $100,000 per year) had higher credit scores. He obtained a random sample of 41 high-income individuals and found the sample mean credit score to be 721.3 with a standard deviation of 80.9. Conduct the appropriate test to determine if high-income individuals have higher credit scores at the a= 0.05 level of significance. State the null and alternative hypotheses. Ho H H₁ H (Type integers or decimals. Do not round.) Identify the t-statistic. to = (Round to two decimal places as needed.) Identify the P-value. P-value= (Round to three decimal places as needed.) Make a conclusion regarding the hypothesis. the null hypothesis. There…

A credit score is used by credit agencies (such as mortgage companies and banks) to assess the creditworthiness of individuals. Values range from 300 to 850, with a credit score over 700 considered to be a quality credit risk. According to a survey, the mean credit score is 710.6. A credit analyst wondered whether high-income individuals (incomes in excess of $100,000 per year) had higher credit scores. He obtained a random sample of 48 high-income individuals and found the sample mean credit score to be 723.6 with a standard deviation of 81.2. Conduct the appropriate test to determine if high-income individuals have higher credit scores at the a = 0.10 level of significance. Click the icon to view the table of critical t-values. State the null and alternative hypotheses. Fill in the correct answers below. Ho: Hyi H (Type integers or decimals. Do not round.) Identify the t-statistic. to = (Round to two decimal places as needed.) Approximate the P-value. The P-value is in the range Make…

The state highway department is studying traffic patterns on one of the busiest highways in the state. As part of the study. the department needs to estimate the average number of vehicles that pass an intersection each day. One of the department's officer (Officer A) claims that on average, more than 15,000 cars passing the intersection. On the other hand. Officer B claims that on average, 18,000 cars passing the intersection. Meanwhile, a random sample of 64 days gives a sample mean of 14,205 cars and a sample standard deviation of 1,010 cars. Test both claim at 0.05 level of significance. Use the critical value approach and show the complete calculation steps for each testing. Whose claim is true? Testing Officer A's claim Step 1: State the hypotheses Step 2: Find critical value and state the decision rule Step 3: Compute the test value Step 4: Make decision Step 5: Conclusion Testing Officer B's claim Step 1: State the hypotheses Step 2: Find critical value and state the decision…

A credit score is used by credit agencies (such as mortgage companies and banks) to assess the creditworthiness of individuals. Values range from 300 to 850, with a credit score over 700 considered to be a quality credit risk. According to a survey, the mean credit score is 708.5. A credit analyst wondered whether high-income individuals (incomes in excess of $100,000 per year) had higher credit scores. He obtained a random sample of 43 high-income individuals and found the sample mean credit score to be 723.3 with a standard deviation of 84.6. Conduct the appropriate test to determine if high-income individuals have higher credit scores at the a = 0.05 level of significance. State the null and alternative hypotheses. Ho: H (Type integers or decimals. Do not round.) Identify the t-statistic. to = (Round to two decimal places as needed.) Identify the P-value. P-value = (Round to three decimal places as needed.) Make a conclusion regarding the hypothesis. the null hypothesis. There…

A credit score is used by credit agencies (such as mortgage companies and banks) to assess the creditworthiness of individuals. Values range from 300 to 850, with a credit score over 700 considered to be a quality credit risk. According to a survey, the mean credit score is 705.8. A credit analyst wondered whether high-income individuals (incomes in excess of $100,000 per year) had higher credit scores. He obtained a random sample of 37 high-income individuals and found the sample mean credit score to be 721.3 with a standard deviation of 81.9. Conduct the appropriate test to determine if high-income individuals have higher credit scores at the a = 0.05 level of significance. State the null and alternative hypotheses. Họ: H H1: H (Type integers or decimals. Do not round.)

A Michigan study concerning preference for outdoor activities used a questionnaire with a six-point Likert-type response in which 1 designated "not important" and 6 designated "extremely important." A random sample of n1 = 41 adults were asked about fishing as an outdoor activity. The mean response was x1 = 4.9. Another random sample of n2 = 50 adults were asked about camping as an outdoor activity. For this group, the mean response was x2 = 5.7. From previous studies, it is known that ?1 = 1.6 and ?2 = 1.5. Does this indicate a difference (either way) regarding preference for camping versus preference for fishing as an outdoor activity? Use a 5% level of significance.Note: A Likert scale usually has to do with approval of or agreement with a statement in a questionnaire. For example, respondents are asked to indicate whether they "strongly agree," "agree," "disagree," or "strongly disagree" with the statement. (a) What is the level of significance? .05   State the null and alternate…

The dataset "nurses" is a random sample of 1,000 cases from “Health Care Provider Credential Data” from Washington State Open Data Portal. In the sample, there are 418 CNA's and 278 of the CNA's have expired credentials. Use the statistics from the nurses dataset to answer the following question: "With 90% confidence, what percent of all CNA's on Washington State's healthcare provider list are expired?"

A credit score is used by credit agencies (such as mortgage companies and banks) to assess the creditworthiness of individuals. Values range from 300 to 850, with a credit score over 700 considered to be a quality credit risk. According to a survey, the mean credit score is 709.6. A credit analyst wondered whether high-income individuals (incomes in excess of $100,000 per year) had higher credit scores. He obtained a random sample of 39 high-income individuals and found the sample mean credit score to be 724.1 with a standard deviation of 81.5. Conduct the appropriate test to determine if high-income individuals have higher credit scores at the g = 0.05 level of significance. State the null and alternative hypotheses. Ho: H = 709.6 H1: µ > 709.6 (Type integers or decimals. Do not round.) Identify the t-statistic. tn = (Round to two decimal places as needed.)