Two new drugs are being compared for effectiveness in lowering total cholesterol levels. On the sample of 15 subjects, drug A is found to lower total cholesterol by an average of 75 mg/dl with SS = 2025. On the sample of 10 subjects, drug B lowered the mean cholesterol level by 78 mg/dl with SS = 2005. Use a 0.01 level of significance to test the claim that the two drugs are equally effective assuming populations are normally distributed. ( Use equal variance t procedure called pooled variance
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Two new drugs are being compared for effectiveness in lowering total cholesterol levels. On the sample of 15 subjects, drug A is found to lower total cholesterol by an average of 75 mg/dl with SS = 2025.
On the sample of 10 subjects, drug B lowered the
mean cholesterol level by 78 mg/dl with SS = 2005.Use a 0.01 level of significance to test the claim that the two drugs are equally effective assuming populations are
normally distributed . ( Use equal variance t procedure called pooled variance t procedure )
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- A large manufacturing company investigated the service it received from its suppliers and discovered that, in the past, 41% of all material shipments were received late. However, the company recently installed a just-in-time system in which suppliers are linked more closely to the manufacturing process.A random sample of 150 deliveries since the just-in-time system was installed reveals that 29 deliveries were late. If we want to test whether the proportion of late deliveries was reduced significantly at α = 0.10. Calculate the null and alternative hypothese.Tardigrades, or water bears, are a type of micro-animal famous for their resilience. In examining the effects of radiation on organisms, an expert claimed that the amount of gamma radiation needed to sterilize a colony of tardigrades no longer has a mean of 900 Gy (grays). (For comparison, humans cannot withstand more than 10 Gy .) A study was conducted on a sample of 27 randomly selected tardigrade colonies, finding that the amount of gamma radiation needed to sterilize a colony had a sample mean of 907 Gy , with a sample standard deviation of 17 Gy . Assume that the population of amounts of gamma radiation needed to sterilize a colony of tardigrades 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 μ , the mean amount of gamma radiation needed to sterilize a colony of tardigrades, is not equal to 900…Tardigrades, or water bears, are a type of micro-animal famous for their resilience. In examining the effects of radiation on organisms, an expert claimed that the amount of gamma radiation needed to sterilize a colony of tardigrades no longer has a mean of 900 Gy (grays). (For comparison, humans cannot withstand more than 10 Gy .) A study was conducted on a sample of 27 randomly selected tardigrade colonies, finding that the amount of gamma radiation needed to sterilize a colony had a sample mean of 907 Gy , with a sample standard deviation of 17 Gy . Assume that the population of amounts of gamma radiation needed to sterilize a colony of tardigrades 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 μ , the mean amount of gamma radiation needed to sterilize a colony of tardigrades, is not equal to 900…
- Tardigrades, or water bears, are a type of micro-animal famous for their resilience. In examining the effects of radiation on organisms, an expert claimed that the amount of gamma radiation needed to sterilize a colony of tardigrades no longer has a mean of 1350 Gy (grays). (For comparison, humans cannot withstand more than 10 Gy .) A study was conducted on a sample of 18 randomly selected tardigrade colonies, finding that the amount of gamma radiation needed to sterilize a colony had a sample mean of 1375 Gy , with a sample standard deviation of 75 Gy . Assume that the population of amounts of gamma radiation needed to sterilize a colony of tardigrades 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 μ , the mean amount of gamma radiation needed to sterilize a colony of tardigrades, is not equal to 1350 Gy .. A taxi company has been using Brand A tires, and the distribution of kilometers to wear-out has been found to be approximately normal with mean =114,000 and σ = 11,600. Now it tries 12 tires of Brand B and finds a sample mean 117,200. Test at the 5% level of significance to see whether there is a significant difference (positive or negative) in kilometers to wear-out between Brand A and Brand B. In the problem above, if the true kilometers to wear-out is 114,000, what is the 95% confidence interval for sample means? First show how to get the critical z values.Given that age of ECU students is normally distributed. A random sample of 16 students had an average age of 25 years and a variance of 4 square years. The 98% CI for the true average age of all ECU students is?
- The director of an obesity clinic in a large northwestern city believes that drinking soft drinks contribute to obesity in children. To determine whether a relationship exists between these two variables, she conducts the following pilot study. Eight- 12-year-old male volunteers are randomly selected from children attending a local junior high school. Parents of the children are asked to monitor the number of soft drinks consumed by their child over a one week period. The children are weighed at the end of the week and their weights converted into body mass index (BMI) values. The BMI is a common index used to measure obesity and takes into account both height and weight. An individual is considered obese if they have a BMI value 30. The following data or collected: child. # of soft drinks consumed BMI 1 3 20 2 1 18 3…A large manufacturing company investigated the service it received from its suppliers and discovered that, in the past, 38% of all material shipments were received late. However, the company recently installed a just-in-time system in which suppliers are linked more closely to the manufacturing process. A random sample of 150 deliveries since the just-in-time system was installed reveals that 33 deliveries were late. If we want to test whether the proportion of late deliveries was reduced signicantly at = 0:10 the null and alternative hypotheses are a. Null hypothesis (H0) b. Alternative hypothesis (HA)