GCSE Secondary Maths Age 13-17 - Ratio, Proportion & Rates of Change: Percentages - Explained

The video tutorial explains how to estimate the population growth of a city using a constant rate of 5.2% per year. Starting with a population of 1,560,000 in 2015, the tutorial demonstrates calculating the population for 2017 using compound interest. It further predicts when the population will reach 2 million, concluding it will be in 2020. The tutorial also discusses the impact of incorrect growth rate assumptions on predictions. The video concludes with a review of the questions and marks allocation.

What was the initial population of the city at the beginning of 2015?

• 2,000,000

• 1,000,000

• 1,560,000

• 1,720,000

What is the formula used to calculate the population after a certain number of years with a constant growth rate?

• Initial Population / (1 + Growth Rate) ^ Number of Years

• Initial Population * Growth Rate * Number of Years

• Initial Population + (Growth Rate * Number of Years)

• Initial Population * (1 + Growth Rate) ^ Number of Years

What was the estimated population of the city at the beginning of 2017, rounded to three significant figures?

• 1,720,000

• 1,730,000

• 1,740,000

• 1,750,000

What is the significance of rounding the population estimate to three significant figures?

• It reduces the number of calculations needed.

• It simplifies the calculation process.

• It ensures consistency in reporting.

• It provides a more accurate estimate.

In which year is the population expected to reach 2,000,000 according to the calculations?

• 2019

• 2021

• 2018

• 2020

Why might the calculation of the year the population reaches 2,000,000 be considered trial and error?

• Because the initial population is unknown.

• Because the growth rate is variable.

• Because multiple calculations are needed to find the exact year.

• Because the growth rate is too high.

What is the impact of assuming a lower growth rate than the actual rate on the year the population reaches 2,000,000?

• The population will reach 2,000,000 later than expected.

• The population will reach 2,000,000 sooner than expected.

• The population will never reach 2,000,000.

• The population will reach 2,000,000 at the same time.