CORE MATHS - MR GREENDLAND + MRS FISHBURNE + MR TETLOW

what does 0-x mean?

sigma

What does sigma mean/show?

how spread out the data is

Correlation does……

not equal causation

What does the higher standard deviation mean?

on average the numbers are further apart

Discrete

counted

Continuous

measured

Qualitative

quality

Quantitative

quantity/numbers

Is discrete finite/infinite?

finite

What does finite mean?

can be listed

Is continuous finite/infinite?

infinite

What does infinite mean?

cannot be listed

What is the symbol for mean/average?

x with a line on top

What is the symbol for standard deviation

O-

What does a lower mean/average mean?

Better/the best score

What does a lower standard deviation mean?

More consistent

How do you calculate interquartile range?

Find the middle of the set of numbers, find the upper quartile and the lower quartile

Then subtract the upper quartile from the lower quartile

What is simple interest?

Interest calculated only on the original amount

What is compound interest?

Interest calculated on the original amount plus accumulated interest

What are the 3 aspects of fermi estimation? (and the marks)

• assumption (2 marks)

• method (1 mark)

• final estimate (1 mark)

What is fermi estimation?

Using values that we known of, to make an estimate

How much is each section of a box plot?

1/4

What are the 2 sentences you write for a box plot question?

• range

• median

Eg. The median was higher for * class so this means (heavier, faster, more expensive)

The range for * class was higher therefore (weigh less, slower, less expensive)

What the equation for histograms?

Frequency density = frequency divided by class width

How do find x bar on a calculator using histogram data?

Find midpoint and frequency

How do you find median from a histogram?

Find the areas of each rectangle/bar and add them all up, and divide by 2

What does random mean?

Every piece of data has equal change of being selected

What is the benefits and drawbacks of random?

Advantage - no bias

Disadvantage - slow

What does stratified mean?

Data is selected proportional to the population

What are the benefits and drawback of stratified?

Advantage - proportional

Disadvantage - bias

What does systematic mean?

The door to door politician (every 5th door)

What are the benefits and drawbacks of systematic?

Advantage - easy

Disadvantage- bias

What does quota mean?

You collect data until your done

What are the benefits and drawbacks of quota?

Advantage - you know how much date you will be getting

Disadvantage - time consuming

What is the name of the other sampling method?

Cluster

What are the benefits and drawbacks of cluster sampling?

Advantage - quick

Disadvantage- bias

In terms of correlation, what is the letter it is called?

r

What is the r called?

Product moment correlation coefficient (PMCC)

Which 2 numbers is it always between?

1 and -1

What does the further from 0 means in terms of the strength of correlation?

Stronger correlation

What does correlation mean?

Measures the strength and polarity of a relationship

What is inflation?

The rate at which the price of products and services have changed compared to a previous point

What does high inflation mean?

Prices are rising quickly

What does low inflation mean?

Prices are still rising but slowly

What does deflation mean?

Prices are decreasing

Why did inflation rocket in 2022?

Russia and Ukraine war - oil prices

What is core inflation?

Inflation but excluding food or energy prices because they tend to be very volatile

What do index numbers always use?

A base number - set to 100

What does CPI stand for?

Consumer price index

How is CPI calculated?

Basket of goods (weighted according to their importance)

What does RPI mean?

Retail price index

What does RPI include which CPI doesn't?

Includes housing costs (mortgages, council tax, house prices

How do you calculate an index number?

New amount divided by original amount x100

What is the target the Bank of England set inflation to?

2%

When inflation was above target, what did the BOE do?

Increased interest rates

What did the increase in interest rates do?

Made borrowing more expensive, so people had less money to spend, and encouraged to save more

What are the 2 exchange rates?

• we buy

• we sell

What does we buy mean?

Converting foreign currency back to £

What do you do for we buy?

Divide

Divide by the buy rate to convert back euros into pounds

What does we sell mean?

Converting £ to foreign currency

What do you do for we sell?

Multiply

Multiply by the sell rate to convert pounds into euros

What do you do if your of know how many euros you want?

Divide the euros by the sell rate

What does it mean if the bank charges 2.5% commission?

2.5% of your money does not get converted

What are the 2 types of extracting data?

• interpolation

• extrapolation

What is interpolation?

Finding a value within the data

What is extrapolation?

Finding a value outside the data

What is the equation for a regression line?

y = a + bx

If a question asks you to "state" correlation, what do you write?

Positive/negative Strong/weak

What is dependent and independent variable?

One depends on the other (distance depends in diesel used)

What goes on the y axis?

Dependent variable

What goes on the x axis?

Independent variable

What is the symbol for standard deviation?

0-x

What does a negative correlation mean?

Too far out of the data - not necessarily true

What does a causal link mean?

One makes the other happen

How do you calculate a regression line?

1. Plot points on x and y axis

2. Use y=a+bx and put in y and x values using start and end data

3. Plot points and draw line

If a question asks you to estimate using a regression line what do you do?

Use the line to estimate an answer

How do you do interations?

Type the given term into the calculator

Then type the equation in using the ANS button

Keep pressing = to get the specific term

What does Xn mean?

The initial term

What is the name of the curve that shows normal distribution?

The Bell Curve

What is it called where the x and y axis meet?

Mew - u with a tail

What does it mean if the curve is higher?

More likely to happen

What does the Bell Curve have to be?

Symmetrical

What is the peak on the Bell Curve?

Mean, median and mode

What are the 2 symbols that stands for the mean?

x bar

Mew

What is the IQ equation?

IQ ~ N(100, 15 squared)

What does 100 stand for in this equation?

What does the 15 and 15 squared stand for?

100 - mean

15 - standard deviation (x-)

15 squared - 225 - variance

What is the symbol for thr mean and what is it called?

Mew - u with a tail

What does the 15 represent?

Standard deviation

What is the symbol, for standard deviation and what is it called?

O- sigma

What does the 15 squared (225) represent?

Variance

Where does the mean always go on a bell curve?

Where the axis cross at the bottom

If the question only gives you X-N(100,25)

What does 25 represent, and what do you do to find thr SD?

25 represents the variance

So you have the square root the 25, to get the SD - which would be 5

What will 2/3 of the death always be within?

1 of the mean

95% of the data will be within what?

2 SD of the mean

Virtually all will be within what?

3 of the mean

How do you add, subtract, multiple and divide on an excel spreadsheet?

Always put = and type cells

Add - (=B2+C2)

Subtract - (=B2-C2)

Multiply - (=B2*C2)

Divide - (=B2/C2)

How do you use the SUM function?

Click on the cell you want the want the answer to appear in

Type in = SUM()

Drag and choose which cells you would like to add

Press enter and it should give you the answer

What is the quickest way of finding the median, LQ and UQ from a histogram?

Using a calculator

What do you type in the calculator?

Midpoint and frequency

Which number goes where the x and y axis cross?

The mean (mew)