In a 2005 study 2205 adolescents aged 12 - 19 years old were give a treadmill test to check their cardiovascular health. 750 of the subjects were determined to have poor cardiovascular fitness. The researchers want to claim that more than 30% of adolescents have poor cardiovascular health (with a 5% level of significance).   The research hypothesis is Ha : p > 0.30. Complete the test by computing the test statistic, the p-value, and stating your conclusions.

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 software company is interested in improving customer satisfaction rate from the 60% currently claimed. The company sponsored a survey of 148 customers and found that 95 customers were satisfied. What is the test statistic z?

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…

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 704.9. 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 33 high-income individuals and found the sample mean credit score to be 717.9 with a standard deviation of 83.9. 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: µ 704.9 H1: µ > 704.9 (Type integers or decimals. Do not round.) Identify the t-statistic, to = (Round to two decimal places as needed.)

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 software company is interested in improving customer satisfaction rate from the 65% currently claimed. The company sponsored a survey of 248 customers and found that 170 customers were satisfied. What is the test statistic z?

A company claims that less than 30% of people who both work and live in Newcastle. A study revealed that among a random sample of 200 people working in Newcastle, 62 also lived in Newcastle. Does the sample support the company’s claim? Use a level of significance of 0.01.

A statistician changes her level of significance from .001 to .05.  What impact will this change have on her risk of making a Type I and Type II error?  Is the change in the level of significance a good decision?  Why or why not?

study is designed to investigate whether there is a difference in response to various treatments in patients with rheumatoid arthritis. The outcome is patient's self-reported effect of treatment. The data are shown on the next page. Is there a significant difference in effect of treatment? Hint: Are severity of symptoms and treatment independent? Run the test at a 5% level of significance. Demonstrate the five steps for hypothesis testing and draw a conclusion based on your results. Remember to determine the p- value, if relevant. No Effect Symptoms Total Symptoms Worsened Improved Treatment 1 22 14 14 50 Treatment 2 14 15 21 50 Treatment 3 9 12 29 50