According to a study on reptiles from decades ago, the mean lifespan of giant Aldabra tortoises in the wild is 89.2 years. Many of the areas where these tortoises live have become polluted with plastic waste. Because of this, a biologist claims the mean lifespan of these tortoises has decreased. To test this claim, the biologist conducted a study of 17 randomly selected, giant Aldabra tortoises in the wild. In the study, the sample mean lifespan was 88.3 years with a sample standard deviation of 1.8 years. Assume that the population of lifespans of giant Aldabra tortoises in the wild is approximately normally distributed. Complete the parts below to perform a hypothesis test to see if there is enough evidence, at the 0.05 level of significance, to support the claim that u, the mear lifespan of giant Aldabra tortoises in the wild, is now less than 89.2 years. (a) State the null hypothesis Ho and the alternative hypothesis H, that you would use for the test. H: 0 O

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 708.2. 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 31 high-income individuals and found the sample mean credit score to be 723.3 with a standard deviation of 80.9. Conduct the appropriate test to determine if high-income individuals have higher credit scores at the α = 0.05 level of significance. C State the null and alternative hypotheses. Ho: HY H₁: (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.…

Liu et al. (2015) recently reported the results of a study examining whether happy people live longer. The study followed a large sample of British women, aged 50 to 69, over a 10-year period. At the beginning of the study, the women were asked several questions including how often they felt happy. After 10 years, roughly 4% of the women had died. The following table shows a frequency distribution similar to the results obtained in the study. Lived Died Within 10 Years Total Happy Most of the Time 382 18 400 Unhappy Most of the Time 194 6 200 Total 576 24 n = 600 Do the data indicate a significant relationship between living longer and being happy most of the time? Test with α = .05. (Round your answers to two decimal places for χ²-critical and χ².) χ²-critical = χ² = Conclusion: Fail to reject the null hypothesis. There is a relationship between living longer and being happy most of the time. Reject the null hypothesis. There is no relationship between living longer and being…

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 704.5. 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 36 high-income individuals and found the sample mean credit score to be 714.9 with a standard deviation of 81.7. 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 V H1: H V (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. V the null hypothesis.…

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…

Anterior cruciate ligament (ACL) injuries occur most frequently in planting and cutting sports such as basketball, soccer, and volleyball. National collegiate athletic association injury data show that female athletes injure the ACL more frequently than their male counterparts do. A sports medicine professor wants to test this claim. He surveyed 5 universities that had both men's and woman's basketball, soccer, and volleyball and asked them how many grade 3 ACL tears they had during the past 5 seasons. Using the following results, are women at greater risk than men for ACL injuries? (use a standard deviation of 0.01, one tail test). Women- 4,3, 5, 2,4 Men-  2, 0, 1 ,2, 1   Calcualte the sum of squares of injuries for men.

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 plant-breeding department at a major university developed a new hybrid boysenberry plant called Stumptown Berry. Based on research data, the claim is made that from the time shoots are planted 90 days on average are required to obtain the first berry. A corporation that is interested in marketing the product, tests 60 shoots by planting them and recording the number of days before each plant produces its first berry. The sample mean is 92.3 days. The corporation will not market the product if the mean number of days is more than the 90 days claimed. The hypotheses are: H0:μ = 90 H1:μ > 90 What is a type I error in the context of this problem

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.)