1. Setting the significance level at a very high cutoff (such as 15%) increases chances of what type of error? 2. Why do Type II errors concern scientists? 3. Why have confidence levels of significance been set at 5% and 1%? 4. Failing to reject the null hypothesis when the research hypothesis is true is referred to
A consumer advocacy group is doing a large study on car rental practices. Among other things, the consumer group would like to do a statistical test regarding the mean monthly mileage, , of cars rented in the U.S. this year. The consumer group has reason to believe that the mean monthly mileage of cars rented in the U.S. this y
A randomized trial comparing the efficacy of two drugs showed a difference between the two (with a P value < .05). Assume that in reality, however, the two drugs do not differ. This is therefore an example of a Type I error. Why is it NOT a Type II error? Is it because Type II error are defined as decision: conclude treatments a
Supposed you were interested in knowing the mean score for a certain quiz in a statistics class with 20 students. You sample four members of the class and find their scores to be 49, 56, 72, and 90. The professor reports that the mean was 72, but you are not sure that is correct. List the four possibilities and categorize th
A manufacturer of handheld calculators receives very large shipments of printed circuits from a supplier. It is too costly and time-consuming to inspect all incoming circuits, so when each shipment arrives, a sample is then used to test H0: pi = 0.05 versus HA: pi > 0.05, where is the true proportion of defectives in the shipme
Pharmadex sells four drugs. It costs Pharmadex $50,000 per year per salesperson. The annual revenue generated from each drug is a function of the number of salespeople assigned to the drug. This dependence is shown in the table below, where Si is the number of salespeople assigned to drug i , and revenue is expressed in thousand
Pharmadex sells four drugs. It costs Pharmadex $50,000 per year per salesperson. The annual revenue generated from each drug is a function of the number of salespeople assigned to the drug. This dependence is shown in the table below, where Si is the number of salespeople assigned to drug i , and revenue is expressed in thousand
2. Two different companies have applied to provide cable television service in a certain region. Let p denote the proportion of all potential subscribers who favor the first company over the second. Consider testing H0 : p = .5 vs HA : P ≠.5 based on a random sample of 25 individuals. Let X denote the number in the sample wh
Please help with the following problem. Explain in easy to understand language what the impact of a Type I or Type II Error for the specific problem and hypothesis attached.
1. "Our sample size was sufficient to detect a ... 10 point difference in [severity] scores between the groups with over 80% power. However, over 150 subjects would be required to detect a difference between groups of 20% in the percentage of cases with weight loss with 80% power." These authors did not find a difference in [sev
Please identify a research question that can be addressed with a hypothesis test. An example might be to identify the presence of bacteria in a batch of milk. Define your research question as a statement. What is your measurement parameter? What is the critical value? Now express your research question as a null
The Money & Investing section of The Wall Street Journal contains a summary of daily investment performance for stock exchanges, overseas markets, options, commodities, futures, and so on. In the New York Stock Exchange section, information is provided on each stock's 52 week high price per share, 52 week low price per share,
Subject: sample Question Details: A movie theater owner wanted to know how many people hated commercial at the beginning of movies if less then 10% hated the commercials the he would leave them. If more than 10% surveyed hated the commercial then they would cancel. A sample of 100 people we surveyed. 14 patrons surveyed as hat
It is claimed that a new treatment for prolonging the life of patients with leukemia is more effective than previous treatments. The null and research or alternative hypotheses for a data set are: Ho: mu < 10.6 years and Ha: mu > 10.6 years (claim). a. State the research conclusion that was written if Ho was rejected and a
It is claimed that a new treatment for prolonging the life of patients with leukemia is more effective than previous treatments. The null and research or alternative hypotheses for a data set are: Ho: mu < 10.6 years and Ha: mu > 10.6 years (claim). a. State the research conclusion that was written if Ho was rejected and