A-level results day has arrived, with millions of students across the country eagerly awaiting their grades this Thursday morning (August 15).
For some, it’s a moment of jubilation as they find out if university is on the cards, while for others, it’s a day to likely forget. As students brace themselves to discover their fate, we thought we’d test your knowledge.
You might not recall how challenging your A-levels were, so why not jog your memory?
TikTok user @freemathstutor_uk, who boasts a following of 64,100, shared a tricky maths question that will have you scratching your head.
If you’re under the impression it’ll be a breeze because it’s just numbers, you’re in for a surprise. In a recent video, the tutor posted an A-level paper 3 maths question on a “must-know” topic.
The question reads: “A team game involves solving puzzles to escape from a room. Using data from the past, the mean time to solve the puzzles and escape from one of these rooms is 65 minutes with a standard deviation of 11.3 minutes.
“After recent changes to the puzzles in the room, it’s claimed the mean time to solve the puzzles and escape has changed. To test this claim, a random sample of 100 teams is selected.
“The total time to solve the puzzles and escape for the 100 teams is 6,780 minutes. Assuming the times are normally distributed, test at the 2% level the claim the mean time has changed.”
The TikTok user provided a detailed explanation on how to approach a seemingly tricky question. To start, one must understand what a mean is: it’s the sum of all numbers divided by the count of those numbers.
Then, it’s crucial to describe the original data distribution. The tutor demonstrates the given set-up, enabling you to calculate the answer.
He determined there was evidence indicating the mean time had altered.
After the complex calculations in the seven-mark question, the tutor concluded: “Therefore we reject the H0 (null hypothesis) and there is sufficient evidence to show the mean time has changed.”
Since its recent posting, the video amassed over 1,900 likes and numerous comments. One TikTok user expressed their gratitude with: “Amazing thank you!” Another commented: “I’m so cooked.”
A third viewer queried: “Why is the mean for the sample set still 65? Should it not be 67.8?” The user clarified: “No it’s the mean for the distribution of sample means which is still the same as the original population mean, so it remains 65.”
