Question 1: Plot the points (x, y): (1, 5), (2, 3), (3, 1), (4, -1), (5, -3) on the grid. Describe the trend.

Answer: Points form a downward trend, indicating negative correlation.

Question 2: Calculate the correlation coefficient for the data points: (x, y): (1, 4), (2, 2), (3, 0), (4, -2), (5, -4).

Answer: -1

Question 3: If the temperature (°C) rises, the amount of ice in a pond (litres) decreases. The data points are: (temp, ice): (0, 20), (10, 15), (20, 10), (30, 5), (40, 0). Plot these points.

Answer: Points show a negative trend; as temperature increases, ice decreases.

Question 1: A researcher records the level of pollution (PM2.5) and the number of birds sighted in different areas. The data show a negative correlation. Explain what this indicates about the relationship between pollution and bird sightings.

Answer: As pollution levels increase, the number of birds sighted decreases, indicating a negative relationship between pollution and bird populations.

Question 2: Given the data points (x, y): (1, 7), (2, 5), (3, 3), (4, 1), (5, -1), find the line of best fit and state its slope.

Answer: Line of best fit has a slope of -2.

Question 3: A study shows that the amount of rainfall (mm) and the growth rate of plants (cm/week) are negatively correlated. Describe how this relationship could influence planting strategies.

Answer: Gardeners might avoid planting in areas expecting high rainfall, as increased rain could hinder plant growth.

Question 1: Data collected from lakes over several years shows that as acid levels (pH) increase, fish populations decrease. Plot the data points: (pH 5, fish count 100), (pH 6, 80), (pH 7, 60), (pH 8, 40), (pH 9, 20). What does the trend suggest?

Answer: There is a negative correlation; higher pH levels are associated with lower fish populations.

Question 2: A forest survey finds that as the number of trees cut down increases, the population of certain bird species decreases. If the data points are: (trees cut: 0, birds: 50), (10, 40), (20, 30), (30, 20), (40, 10). Plot these points.

Answer: Points show a negative correlation; more trees cut, fewer birds.

Question 1: The data indicates that as the pH level of soil increases, the growth rate of certain plants decreases. The data points are: (pH 4, 15cm), (pH 5, 12cm), (pH 6, 9cm), (pH 7, 6cm), (pH 8, 3cm). Calculate the correlation coefficient and interpret its value.

Answer: -1, indicating a perfect negative correlation.

Question 2: Design a scatter graph to illustrate the relationship between altitude (meters) and plant diversity in a mountain environment. Describe the expected trend based on environmental principles.

Answer: Expected to show a negative trend; higher altitude generally correlates with lower plant diversity.

Question 1: Identify the mistake in the following statement: 'A negative correlation means that as one variable increases, the other also increases.'

Answer: The statement is incorrect because negative correlation means as one variable increases, the other decreases.

Question 2: Which of the following best describes a negative correlation? A) Data points form an upward trend B) Data points are randomly scattered C) Data points form a downward trend D) Data points are clustered tightly with no trend

Answer: C