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NBT Data Interpretation & Analysis 3 Flashcards

6 cards from real NBT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 NBT Data Interpretation & Analysis 3 flashcards as text

  1. A box-and-whisker plot shows: minimum = 20, Q1 = 35, median = 50, Q3 = 65, maximum = 80. What is the interquartile range (IQR)?

    Answer: 30

    IQR = Q3 - Q1 = 65 - 35 = 30.

  2. A frequency distribution shows: scores 0–49 (15 students), 50–74 (45 students), 75–100 (40 students). What percentage of students scored below 50?

    Answer: 15%

    Total: 15 + 45 + 40 = 100 students. Percentage below 50: 15 ÷ 100 = 15%.

  3. Two datasets have the same mean but different standard deviations (SD₁ = 2, SD₂ = 10). What can be concluded?

    Answer: Dataset 2 has more spread around the mean

    Standard deviation measures the spread of data around the mean. Dataset 2 (SD = 10) has much more variability — its values are more spread out from the mean than Dataset 1 (SD = 2).

  4. A regression line on a scatter plot has the equation y = 3x + 5. What does the slope (3) tell us?

    Answer: For every 1-unit increase in x, y increases by 3

    The slope of a linear equation represents the rate of change. A slope of 3 means that for every 1-unit increase in x, the predicted value of y increases by 3.

  5. A researcher claims that because crime rates and ice cream sales both rise in summer, ice cream causes crime. What is wrong with this reasoning?

    Answer: Correlation does not imply causation — both are affected by a third variable (heat/summer)

    This is a classic confounding variable (lurking variable) example. Both variables are influenced by a third factor (hot weather/summer) — not by each other. Correlation ≠ causation.

  6. A sample of 200 students has a mean score of 60 with a standard deviation of 10. Assuming a normal distribution, approximately what percentage of students scored between 50 and 70?

    Answer: 68%

    In a normal distribution, approximately 68% of data falls within one standard deviation (±1 SD) of the mean. Mean ± 1 SD = 60 ± 10 = [50, 70]. Approximately 68% scored in this range.