Practice: information and representations
Practice: information and representations
In one year:
Town A has 18,000 residents, and had 54 burglaries of homes.
Town B has 75,000 residents, and had 150 burglaries.
How many burglaries were there in town A for every 1,000 residents?
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
How many burglaries were there in town B for every 1,000 residents?
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
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Town B had more burglaries. Does that mean a home is more likely to be burgled there? Explain.
A news site published a family’s mean monthly electricity bill, in shekels:
How many times as tall as the 2023 bar is the 2024 bar, in the chart?
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
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By what percent did the mean bill really rise?
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A school has 2,400 pupils.
300 of them were chosen at random and asked how they get to school.
105 answered “by bicycle”.
What percent of the sample come by bicycle?
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
Estimate: how many of the school’s pupils come by bicycle?
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
Had only pupils standing by the bicycle racks been asked, would the estimate have been good? Explain.
In an election poll a small party got 8%.
The margin of error: 3.5%.
A party enters the Knesset only if it gets at least 3.25% of the votes – the electoral threshold.
What is the lowest percent of support for the party in the whole population, by the poll and its margin of error?
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
What is the highest percent?
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By the poll, is the party likely to pass the electoral threshold? Explain.
An electricity bill charges 30 ₪ a month, and 0.6 ₪ more for each kilowatt-hour (kWh).
Write a formula for the monthly bill , in shekels, by the number of kWh .
What will the bill be in a month when 400 kWh were used?
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
One month’s bill was 210 ₪. How many kWh were used? Write an equation and solve it.
The graph: the number of cars in a shopping centre’s car park, by the hour of the day – from 6 in the morning to 21 in the evening.
Mark the points where the graph turns from rising to falling or from falling to rising.
Work out the average rate of change from hour 17 to hour 21, in cars an hour.
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power
When were there the most cars in the car park? What might have happened between 9 and 13?
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
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A study found: “Pupils who eat breakfast get higher marks.”
A newspaper wrote: “Breakfast improves marks.”
Does the study show that? Suggest a third factor that could explain the link.
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – check and a new line · * – times · ^ – power, ↓ – end of the power
/ – fraction bar · Tab or the arrows – between numerator and denominator, then a note above or below · Enter – a new line · * – times · ^ – power, ↓ – end of the power