8 4 Scientists studied how perception of risk differs from the actual risk. People were asked to estimate their risk of developing cardiovascular disease (CVD) during their lifetime. This gave their perceived risk. The scientists used information gathered from questionnaires and various tests to calculate a predicted actual risk of developing CVD, for each person. The table shows how the perceived risk given by each person was compared with the predicted actual risk calculated by the scientists. Underestimation of lifetime risk for CVD Correct estimation of lifetime risk for CVD Overestimation of lifetime risk for CVD Perceived risk < predicted actual risk Perceived risk = predicted actual risk Perceived risk > predicted actual risk It was found that some people’s perception of their lifetime risk of developing CVD was different from the predicted actual risk calculated by the scientists. (a) Explain why the perception of the lifetime risk of developing CVD of some people was different from the predicted actual risk. 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Turn over 9 (b) Explain how blood tests and obesity indicators can be used to collect data to predict the risk of developing CVD. 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(Total for Question 4 = 8 marks)