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3. question 11 all of the following statements are correct one...

Question: question 11 all of the following statements are correct one...

Question 11

All of the following statements are correct ONE, please identify the incorrect statement.

 Prevalence is the proportion or percentage of people in a given population who currently have the disease. If data are collected by a cross-sectional survey Prevalence ratio can be used to see if the exposure and outcome are related. Cross-sectional design/survey involves one-off data collection on exposure/s and outcome. Prevalence will decrease if a new drug reduces the mortality associated with the disease, even if it does not result in a cure. Prevalence is a measure of existing cases of the disease either at a particular point or during a period of time and usually expressed as percentage.

Question 12

In a cross-sectional study there were 575 cases of hypertension among 5,980 normal weight patients while 1,414 cases among 2,431 over-weight patients. Calculate Prevalence ratio to investigate if there is a link between excessive body weight and hypertension (Make sure you are choosing 'exposed' and non-exposed groups correctly). Please provide your final answer with two decimals after correct rounding. Use of brackets is strongly recommended otherwise your answer may differ and will be marked incorrect.

Please also remember ratio measures are not expressed as percentage,  so do not multiple with 100.

Question 13

Z scores are expressed/interpreted in terms of number standard deviations; if some one has a z score of -1.5 for weight and 2.1 for height it means this person is 1.5 standard deviations below the average body weight but 2.1 standard deviations above the average for his/her population. Calculate z score for a person if their raw score is 25.62 and the sample mean is 22.79 with standard deviation of 5.81. Two decimals please. If your final answer is a negative number make sure you type in minus sign before the answer, positive answer does not need this.

Question 14

Please  identify  from the following ONE correct null hypothesis for Shapiro-Wilk test of Normality.

 There is no difference in mean blood pressure between the treatment and control groups. Sample data for the test variable have not come from a population with normal distribution. There is no link between an exposure and the outcome. Sample data for the test variable have come from a population with a normal distribution. Study results do not have any statistical significance.

Question 15

What are the two most common descriptive statistics  that are used to describe continuous data that are not skewed?

 Frequency distribution and Range. Mode and Inter Quartile Range (IQR). Standardized score (or z-score) and percentage for each category Median and percentage in each category. Mean and standard deviation Mean and mode