Correctly that the treatment and control groups do not differ with respect to outcome.   That the treatment and control groups do not differ with respect to outcome when in fact they do.   That you don’t have sufficient information to present results.

Consider a study designed to estimate the role that certain characteristics play on predicting persons who are at greatest risk of developing arthritis in one or more joints. The authors have noted a lost-to-followup rate of 26%. Why is this cause for concern?   It is cause for concern because those who remain in the study may be at a systematically higher risk than those not followed   It is not cause for concern in this type of study; the concern exists only for randomized trials   It is cause for concern because those who remain in the study may be at a systematically higher or lower risk than those not followed   It is cause for concern because those who remain in the study may be at a systematically lower risk than those not followed

An early study found that postal workers who worked in the office had higher rates of coronary heart disease than those who delivered mail on foot. The investigators concluded that physical activity is inversely related to risk of developing coronary heart disease. Sceptics disagreed, pointing out that the postal clerks were older than the postal carriers, and that age is a risk factor for coronary heart disease. This argument highlights the possible role of: -Chance? -Selection bias? -Recall bias? -Confounding?

I'm having trouble finding the dependent and independent variables of this scenaro:  Average IQ scores for young school children are known to be 100 (SD = 15).  However, the literature indicates that children’s intelligence may be decreased if their mothers have German measles during pregnancy.  Using hospital records, a researcher obtained a sample of n = 25 school children whose mothers all had German measles during their pregnancies.  Do the data indicate that children born to mothers who had German measles during the pregnancy have significantly lower IQ scores than typical young school children?

In regard to the difference margin (M), which of the following statements is NOT right? a. the difference margin should be chosen before the start of a trial  b. the difference margin is a value randomly chosen by the researchers c. the difference margin is carefully chosen with both statistical and clinical considerations  d. Non-inferiority and equivalence in efficacy between a new treatment and the standard treatment should be claimed in the presence of a well justified difference margin

Lead time bias is best described as   a. an apparently lower survival rate among persons screened compared to an unscreened group   b. a similar survival time for persons identified during a screening program relative to persons who are diagnosed by clinical symptoms   c. an apparently longer survival time among persons identified during a screening program because they were identified at an earlier stage of their disease   d. a truly longer survival time for persons identified during a screening program because they were given an effective treatment

What is regression? How is it used?

For each of the following phenomena, indicate (1) a possible hypothesis to ex- plain it, (2) a possible competing hypothesis, and (3) a test implication for each hypothesis. . In stressful situations, women appear to adapt better and quicker to the emotional demands of the situation than men do. The mosquito population in the county has decreased drastically in the past year even though county workers have curtailed the use of insecti- cides and have stopped urging residents to get rid of standing water on their property, which is a breeding ground for the insects.

Was the control group valid in the Tuskegee study? Why yes or why not? Can you please help me with this question

Specifically, address the difference between the control groups of Brassica rapa plants under natural sunlight versus experimental groups of Brassica rapa plants under artificial light which uses incandescent light bulbs, and how to exactly apply an independent variable which is the duration of light exposure of the Brassica rapa to the experimental group members. Quantify the independent variable. This needs at least a general description of the process that is written in a narrative format and should be 2-3 paragraphs long.