math (unit 3 and 4)

• r value = strength of the correlation
• mean = add all values / number of values
• DST = Daylight Saving Time, +1 for the UTC
• r2 value = variability of the correlation
• r2 to r = square root r value
• r to r2 = square r value
• Deseasonalised Data = number of values / seasonal index
• Strong Correlation = 1
• Weak Correlation = 0-0.4 range
• Moderate Correlation = 0.5 and above
• categorical data = data without numerical values
• numerical data = data with numerical values
• interpolation = data which is within the data range
• extrapolation = data which exceeds the data range given
• extrapolation danger - cannot be sure with data that exceeds the ranges of data as the r and r2 values do not apply to these values, making their correlation to the dataset, unknown and unreliable.
• 3 point moving average = adding 3 values of the dataset / the number of the values (3)
• centred moving avg = same process but divided by the centred value eg: x = 40, divide by 40
• least squares equation = ab + x
• equation of a line = mx + b
• mx = gradient
• b = y-intercept
• y-intercept is where the graph crosses the y axis
• x-intercept = when y is zero
• gradient is how steep the line is
• arithmetic sequence = a sequence of numbers where the sum of the first n terms is equal to the sum of the n+1 terms
• common difference = d
• common ratio = r
• ratio = geometric sequence
• difference = arithmetic sequence
• simple interest = arithmetic sequence
• compound interest = geometric sequence
• appreciation = going up in value
• depreciation = going down in value
• 360/24 = 15 degrees (time zones)
• UTC = Coordinated Universal Time, a time standard that is used to define the time of day in relation to the rotation of the Earth.
• latitude = the angle of the sun at a particular point on the earth's surface
• longitude = the angle of a line passing through the centre of the earth and the point on the earth
• latitude before longitude
• prime meridian = zero degree longitude
• meridian = imaginary lines running from pole to pole