Statistics and Probability

Data that describes a numeric amount or count is called:

The number of words on this page is:

If you use a stopwatch to record the time taken for a chemical reaction to occur, the data is:

Which of the following is NOT a type of quantitative data?

The speed of a car (in km/h) is recorded. This data is:

When data is collected through observation without asking questions, it is called:

What type of data is the 'number of people in a cinema'?

What is the primary benefit of using 'Stratified Sampling' over 'Simple Random Sampling'?

A sample of $200$ items is taken from a production line of $10,000$. If $4$ items are defective, what is the best estimate for the total number of defective items in the whole batch?

In a questionnaire, the response boxes for 'Age' are: $10-20, 21-30, 31-40, 41-50$. A $20.5$-year-old respondent would:

Calculate the range of these values: $19, 11, 15, 20, 12$.

What is the mean of $4, 4, 4, 8$?

Find the mode of the following set: $2, 4, 6, 8, 2$.

Calculate the median of the data: $1, 1, 1, 5, 5$.

Find the mean of the data: $10, 10, 20, 20, 30$.

If the sum of $n$ numbers is $S$, which formula represents the mean?

Determine the range of the following values: $15, 22, 18, 15, 30$.

The range of $5$ numbers is $15$. If every number is doubled and then $5$ is subtracted from the result, what is the new range?

If the mean of $5$ observations is $x$ and the mean of $k$ of these observations is $y$, find the mean of the remaining $5-k$ observations.

A set of $5$ integers has a mean, median, and mode all equal to $10$. If the range is $10$, what is the smallest possible value for the largest number in the set?

A pie chart is used to show the distribution of energy sources. If 'Solar' is $45^\circ$, 'Wind' is $75^\circ$, and the rest is 'Fossil Fuels', what angle represents 'Fossil Fuels'?

Find the range of the data represented in this bar chart.

The line graph shows the growth of a plant. Between which two days was the growth rate the fastest?

The following bar chart shows the number of goals scored by a team. What is the total number of goals scored in these 4 matches?

The histogram shows the heights of plants in a greenhouse. How many plants have a height of at least $20$ cm but less than $40$ cm?

A dual bar chart compares the number of boys and girls in three different clubs. In the Coding club, there are 12 boys and 16 girls. If a new girl joins the club, what will be the new percentage of members in the Coding club who are girls? (Round to 1 decimal place)

The pie chart shows the distribution of students' favorite subjects in a class of 40 students. If the sector for Mathematics has an angle of $108^{\circ}$, how many students chose Mathematics as their favorite subject?

An analyst is looking at a histogram of house prices with variable class widths. The class $[200k, 300k]$ has a frequency density of 5 houses per $1k range. The class$[300k, 500k]$has a frequency density of 2.5 houses per$1k range. If these two classes represent $60\%$ of the total houses in the area, how many houses are there in total?

A composite bar chart shows the energy production of a country from 'Renewable' and 'Non-renewable' sources. In 2010, the total was 500 GW with $20\%$ Renewable. In 2020, the total increased to 800 GW and Renewable sources now make up $45\%$. What is the percentage increase in 'Renewable' energy production from 2010 to 2020?

A company’s quarterly profit is shown in a bar chart. In Q1, the profit was $P$. In Q2, it increased by $20\%$. In Q3, it fell by $10\%$ relative to Q2. If the Q3 profit was $54,000, find the value of$P$ and the total profit for the first three quarters.

A spinner is divided into 6 equal sections numbered 1 to 6. What is the probability of landing on a composite number?

Two independent events X and Y have probabilities $P(X) = \frac{1}{2}$ and $P(Y) = \frac{1}{3}$. What is the probability of both events occurring?

In a standard deck of cards, what is the probability of picking a red card (Heart or Diamond)?

A fair six-sided die is rolled. What is the probability of rolling a number less than or equal to 2?

A letter is chosen from the word 'ALGEBRA'. What is the probability that it is the letter 'A'?

The probability of winning a game is $0.25$. If you play the game 3 times, what is the probability of winning all 3 times?

A bag contains 8 red, 7 blue, and 5 green marbles. What is the probability of picking a marble that is either red or green?

An event $A$ has $P(A) = p$. The probability that $A$ occurs exactly once in two independent trials is $0.42$. Which equation could be used to find $p$?

A student takes a multiple-choice test with 3 questions. Each question has 4 options. If the student guesses randomly, what is the probability of getting exactly 2 questions correct?

A bag contains 5 yellow and 3 orange sweets. A sweet is taken at random and replaced. Then a second sweet is taken. What is the probability that both sweets are orange?

Which of these is a key feature to look for in a scatter diagram to determine the type of correlation?

What is the correlation between the number of hours a candle has been burning and its height?

If we use a line of best fit to predict a value, and the correlation is weak, the prediction is:

What correlation exists between the depth of a hole being dug and the amount of dirt removed?

If all points in a scatter diagram lie on a line with the equation $y = 10 - x$, the correlation is:

A scatter diagram for $x$ (age of a tree) and $y$ (circumference of the trunk) shows a line of best fit passing through $(10, 50)$ and $(30, 130)$. What is the circumference of a tree that is $25$ years old?

A scatter diagram shows a strong negative correlation between altitude and air pressure. If the pressure at $0$ m is $1013$ hPa and at $1000$ m is $899$ hPa, what is the gradient of the line of best fit ($hPa$ per meter)?

What is the best description of a 'line of best fit' in a scatter diagram with no correlation?

A student finds a correlation coefficient of $1.2$ for their scatter diagram. What can you conclude?

Consider a scatter diagram with two distinct clusters of points, each showing a positive correlation, but the clusters are far apart. What might a single line of best fit for all points show?