Maths Skills Flashcards
What is 1mm in um?
1,000 um
What is 1m in mm?
1,000 mm
A section of a quadrat is 10 x 10cm, calculate it’s area in mm.
10cm = 100mm
100 x 100 = 10,000mm^2
a box is 1cm^3 calculate it’s volume in a) mm and b) um
a) 1cm=10mm
10^3 = 1,000mm^3
b) 10mm = 10,000 um
10,000^3 = 1x10^12
what is a rate?
quantity per unit time
ratios
used to compare the relative quantity of two or more things
What is the equation for volume of a sphere?
4/3 x π x r^3
What is the equation for the SA of sphere?
4 x π x r^2
How do we calculate % change
difference / start value
what would be the value of y = 2.85 on a log10 scale?
10^2.85 = 707.9
If a bacteria divides every 20 mins, how many bacteria would there be after 11 hours?
60/20 = 3 divisions an hour
3 x 11 = 33 divisions total
2^33 = 8 589 934 592
what is random sampling?
record samples at random locations to get an unbiased subset of a whole population/area
systematic sampling
sample locations are chosen by scientist eg) line transect
how many dp do we keep when adding?
all
eg) 6.549+4.12+2.1 = 12.769
how many dp do we keep when multiplying or dividing?
keep to the lowest level of accuracy in the question
What is the magnitude?
the amount by which an object has been made bigger
what is resolution?
the shortest distance between two points that can be seen
what is the Order of Magnitude equation?
I = A x M I = image A= actual M = magnification
What does it mean when the the results are more than the critical value at a P value = 0.05 confidence interval?
the results are significant and we can reject the null hypothesis
there is a less than 5% probability that the results are down to chance
what does it mean when the results are less than the critical value at P = 0.05
the results are not significant
we can accept the null hypothesis
What does the SD show?
average variation from the mean
What is the students T Test used for?
comparing the means of 2 data sets
what is Chi squared used for?
compare observed and expected results
What is the correlation Coefficient used for?
used to test the strength of a relationship between two variables
