At the end of the 2024 fishing season on Fork Lake, 60 anglers (amateur fishers) were randomly surveyed. They were asked how many bass they caught over the whole season. The information is summarized in the following frequency table:

Assume that this sample is representative of all anglers in any season, and that all anglers have equal skill.

The U.S Fish and Wildlife Service (USFWS) estimates that the bass population in Lake Fork will grow by 8% between the 2024 and 2025 fishing seasons.

The USFWS wants the bass population to remain unchanged year to year.

The resting body temperature, in degrees °C, of 6 adults is measured and recorded alongside their age, in years, in the table below.

The relationship between Y and C can be modelled by the equation C =aY+b.

A teacher surveys his class to find out how long each student spent studying for a recent test. The time, in hours, each student spent studying is shown alongside their score in the following table.

The mean length of 3 snakes is 1.4m. The first snake is 120cm long, and the second snake is 10cm shorter than the third snake.

A fourth snake is measured, and the mean is recalculated to be 150cm.

The following table shows the data collected in a study.

Dr. Darwin is investigating the clutch size (number of eggs per nest) of the different turtle species that nest on Eagle Island. He samples the island's nests by drawing a circle with a 100m radius centered at random GPS coordinates, and repeats this process a total of 3 times. For every nest in the sampling zones, he records the species and the number of eggs in the nest. The surface area of the island is 4km2.

The 4 different species of marine turtles that lay eggs on the island are:

• The Pacific Green Turtle (PG)

• The Pacific Leatherback Turtle (LB)

• The Indo-Pacific Hawksbill (IH)

• The Olive Ridley Turtle (OR)

The data collected is summarized in the table below.

Dr. Darwin is interested in studying turtle hatching on a chain of 3 islands, Sandy, Blue and Eagle. Dr. Darwin first wants to estimate the total number of nests on the island chain. To do this, he first finds the total surface area of the islands, 22km2. He lands his boat on the sheltered side of the largest island, and draws a 100m by 100m square in the sand starting from the point he came ashore. He then counts the number of nests inside the square, and finds 8.

Dr. Darwin makes a second attempt at data collection. This time, he visits each island, and takes 4 separate 100m×100m samples, one on each side (north, west, south & east) of the island. The data for the number of nests found in each sample are provided in the table below.

Sandy & Blue both have a surface area of 9km.

Perplex conducts a study on student performance in IB math. The scores of 5 students are shown in the following table alongside the number of mock exams each student completed.

The relationship between S and N can be modelled by the regression line N=aS+b.

During a very difficult practice maths quiz, 40 high‑school students each received a mark out of 100.

A passing score is 27 marks.