NLN Updated NEX Exam Questions and Answers by gaia

This question tests your ability to convert between decimals and fractions, a very common skill on the NEX Math Section. Start by understanding the decimal value. The decimal 0.04 means four hundredths, which can be written as the fraction 4/100. The next step is to simplify this fraction by dividing both the numerator and the denominator by their greatest common factor, which is 2. Doing so gives 2/50. That fraction exactly matches option C, making it the correct answer. To verify, you can also convert 2/50 back into a decimal by dividing 2 by 50, which equals 0.04. The other options are incorrect because they represent much larger values. For example, 1/4 equals 0.25, 2/5 equals 0.4, and 2/500 equals 0.004. On the NEX exam, remembering that two decimal places correspond to hundredths can help you quickly form the correct fraction before simplifying.

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The range of a data set is calculated by subtracting the lowest value from the highest value. From the graph, the lowest systolic blood pressure reading appears to be about 125 mmHg, while the highest reading is about 185 mmHg. Subtracting gives: 185 − 125 = 60. Therefore, option B is correct. Option C represents a single high reading rather than a range. Options A and D underestimate the difference. NEX questions involving range require careful identification of extreme values on graphs, so it is important to examine the entire data set, not just the most common values.

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This problem tests estimation and interpretation of scatter plots. The first 10 measurements (before the red line) cluster around an average of approximately 140 mmHg. The second set of 10 measurements (after the red line) cluster around approximately 170 mmHg. To estimate the increase, subtract the earlier average from the later average: 170 − 140 = 30 points. Therefore, option C is correct. Options A and D represent total values rather than the change between averages. Option B overestimates the difference. On the NEX, estimation questions do not require exact calculations; instead, you must identify reasonable average values from visual data and compare them correctly.

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