A scatter plot shows points that cluster close to a straight line. This is called a: — Strong linear association.When points cluster closely around a line, the association is strong (and linear if the line is straight).
A scatter plot shows points loosely scattered around an upward trend. This describes: — Weak positive linear association.Loosely scattered around an upward trend = weak (not tight) positive linear association.
What does an OUTLIER look like in a scatter plot? — A point far from the main cluster.An outlier in a scatter plot is a data point that does not fit the overall pattern — far from the main cluster.
Association in a scatter plot does NOT prove: — Causation (one variable CAUSES the other).Correlation ≠ Causation. Two variables can be associated without one causing the other. They may both be caused by a third variable.
A scatter plot shows a curved pattern (like a U shape). The association is: — Nonlinear.A curved pattern indicates a nonlinear association — the relationship exists but doesn't follow a straight line.
Which scatter plot description suggests the strongest association? — Points forming a tight cluster around a line.Strength of association is shown by how closely points cluster around the trend. Tight clustering = strong association.
A scatter plot for car age vs. resale value would show: — Negative association.Older cars are generally worth less → as age increases, resale value decreases → negative association.
What is the independent variable in a scatter plot comparing study hours (x) and test scores (y)? — Study hours (x).The independent variable (x) is the input you control or measure first. Study hours is placed on the x-axis.
In a scatter plot, data following a curved path (e.g., exponential growth) represents: — Nonlinear positive association.A curved upward path is nonlinear and positive (as x increases, y also increases, just not at a constant rate).
In a scatter plot, as the points scatter more widely around the trend, the association is: — Weaker.Wide scattering around the trend means points are less predictable — the association is weaker.
Which pair would most likely have NO association in a scatter plot? — Lucky number and height.Lucky numbers are arbitrarily chosen and have no relationship to a person's height. This pair would show no association.
y = 5x + 12 models weekly income vs. hours worked. What does the y-intercept 12 represent? — Base pay of $12 regardless of hours.The y-intercept (12) is the predicted value when x = 0. Here, it represents $12 base pay even for 0 hours worked.
A line of best fit is y = 0.8x + 2. For x = 15, what is the predicted y? — 14.y = 0.8(15) + 2 = 12 + 2 = 14.
The line of best fit passes through (0, 20) and (5, 45). What is its equation? — y = 5x + 20.Slope = (45−20)/(5−0) = 25/5 = 5. y-intercept = 20. Equation: y = 5x + 20.
Data ranges from x = 1 to x = 10. Your line of best fit predicts y for x = 50. This is: — Extrapolation — potentially unreliable.x = 50 is far outside the 1–10 data range. This is extrapolation — the trend may not hold that far out.
A line of best fit for temperature (x) vs. ice cream sales (y) has slope 3. This means: — For each degree increase in temperature, ice cream sales increase by about 3.Slope = 3: for each 1-unit increase in temperature, predicted ice cream sales increase by 3 units.
Why might predictions from a line of best fit be imperfect? — Real data has variability — the trend is approximate.Real-world data varies. A line of best fit models the trend, not every individual point. Predictions are estimates, not exact values.
y = −3x + 90 models test scores (y) vs. absences (x). Predict the score for 5 absences. — 75.y = −3(5) + 90 = −15 + 90 = 75.
Which line of best fit equation has a NEGATIVE correlation? — y = −4x + 80.A negative slope (−4) indicates a negative correlation: as x increases, y decreases.
The line of best fit passes through (2, 10) and (8, 22). What is the slope? — 2.Slope = (22−10)/(8−2) = 12/6 = 2.
Using y = 3x + 1, find x if y = 25. — x = 8.25 = 3x + 1 → 3x = 24 → x = 8.
A line of best fit for height vs. weight has equation y = 2.3x − 100. Which value of x (height in cm) is best for interpolation if data ranges from 150–190 cm? — 170 cm.170 cm is within the 150–190 cm range — valid interpolation. The others are outside the data range (extrapolation).
From the table (30 boys soccer, 20 girls soccer, 15 boys tennis, 35 girls tennis): P(soccer | girl) = ? — 20/55.Total girls = 20 + 35 = 55. Girls who prefer soccer = 20. P(soccer | girl) = 20/55 = 4/11.
Two-way table row relative frequency divides each cell by: — The row total.Row relative frequency = cell count ÷ row total. This shows what proportion of each row category falls in each column.
Why use relative frequencies instead of raw counts when comparing groups of different sizes? — Relative frequencies allow fair comparison regardless of group size.Relative frequencies (proportions/percentages) allow fair comparison. If one group has 100 people and another has 500, raw counts are misleading.
Table: 60 adults own cats, 40 adults don't; 30 teens own cats, 70 teens don't. What proportion of adults own cats? — Both a and c (since 60/100 = 60%).Total adults = 60 + 40 = 100. Proportion = 60/100 = 60%. Both a and c express the same value.
From the same table: what proportion of teens own cats? — 30%.Total teens = 30 + 70 = 100. Proportion = 30/100 = 30%.
From the same table: do adults or teens have a higher rate of cat ownership? — Adults (60%) vs. teens (30%) — adults higher.Adults: 60% own cats. Teens: 30% own cats. Adults have twice the cat ownership rate.
Which two-way table check ensures the table is correct? — Row totals and column totals must both add up to the grand total.A correctly filled two-way table has row totals and column totals that each add to the grand total.
A table has row categories "yes" and "no" and column categories "male" and "female." The row totals are 80 and 120. The grand total is 200. What is the relative frequency for "yes" row? — All of the above.80/200 = 40% = 0.40. All three are equivalent representations of the same relative frequency.
Can a two-way table show numerical data? — No — two-way tables are specifically for CATEGORICAL data.Two-way tables organize counts of categorical data. For numerical data, you use scatter plots, histograms, etc.
A two-way table shows 300 students. 150 students are in 7th grade. 90 of the 7th graders prefer STEM subjects. What fraction of 7th graders prefer STEM? — 90/150 = 3/5.Row total for 7th grade = 150. STEM-preferring 7th graders = 90. Fraction = 90/150 = 3/5 = 60%.