Math Skills Flashcards
(20 cards)
In the UK in 2017, there were 805 000 deaths.
Cancer caused 29% of all deaths.
Throat cancer caused 4% of all deaths from cancer.
Calculate the mean number of people who died of throat cancer per month in 2017.
778
(805 000 x 0.29 x 0.04) / 12
Information travels at 120 metres per second in neurones.
Calculate the time it would take for the information to travel 1.8 m along a neurone.
Give your answer in milliseconds (2 sig fig)
15 ms
(1.8/120) x 1000
A ruler has an error of ± 1 mm.
An object’s length was 5.7 mm.
Calculate the % error of uncertainty.
to 2 DP
17.54 %
What is the equation for uncertainty of a measurement?
Reading: (half of smallest interval / reading) * 100
Meauremement: (one interval / actual measurement) *100
Calculate the percentage change in mass [grams]:
Mass before = 6.3 g
Mass after = 2.4 g
(Difference / Original) x 100
(3.9 / 6.3) *100
= 61.9 %
Calculate the mean value:
8.4, 2.5, 4, 1.1, 8.5, 8.5, 7, 2.5, 7.9
8.4+2.5+4+1.1+8.5+8.5+7+2.5+7.9
________________________________________
9
= 5.6
Which P value(s) shows a difference is significant.
a) P=0.06
b) P>0.05
c) P<0.05
d) P<0.50
c) P<0.05
The probability that the difference is due to a random chance event is less than 5%
A scientist determined the volume of a plant cell and the volume of organelles it contained.
They found:
- the volume of a plant cell is 18 500 µm3
- the volume of all the mitochondria in a plant cell is 262.5 µm3
- the volume of all the mitochondria and all the chloroplasts in a plant cell is 46.1% of the volume of a plant cell.
Use this information to calculate the volume of all the chloroplasts in a plant cell.
8266 µm3
18 500 x 0.461 = 8528.5;
8528.5 - 262.5;
Define Standard Deviation.
The spread of data around the mean
Large SD bars indicate…….
A large range of variation in the data.
Less reliable mean value.
Explain the advantage of showing the data using standard deviations rather than ranges.
- SD is spread of data around the mean;
Accept: range is difference between highest and lowest values/extremes or range includes anomalies/outliers.
- (SD) reduces effect of anomalies/ outliers;
Reject: (SD) removes anomalies/outliers.
- (SD) can be used to determine if (difference in results is) significant/not significant/due to chance /not due to chance; or allows a STATS test to be performed to determine if differences are significant.
Which stats test would you use if the data is categoric?
CHI SQUARED
Which stats test would you use to see if there is a relationship between two variables?
Correlation coefficient
Spearman’s Rank
Which stats test would you use to see if there is a difference between two means?
Student T test
If Y = 16.56 find the value of x
y = 0.72x + 4
x= 17.4
The scientists measured the percentage change in tumour volume.
Suggest why they recorded both percentage change and tumour volume.
Percentage change: To allow comparison as tumours may differ in volume/size
Tumour volume: (As) tumours may differ in length/width/shape OR
(As) volume is (best) indication of the number of cells in tumour;
Drug X is delivered at a dosage of 3 ng Kg-1h-1 for 8 days into a patient.
1ng = 1 x10-9 g
Calculate the total mass in grams of drug X injected after 8 days into a patient with a body mass of 82 kg.
[2]
5x10-5;;
3 x (8x24) x 82 = 47232;
47232 / 1 000 000 000;
The concentration of ATP in skeletal muscle is approximately
5 × 10–3 mmol g–1
During maximum exercise, ATP in skeletal muscle is used at a rate of approximately 3.7 mmol kg–1 s–1.
Calculate how long maximum exercise would last if ATP was not resynthesised.
1.35 or 1.4 seconds;;
5x10-3 mmol g-1 x 1000 (Unit conversion)
5/3.7 = 1.35 seconds
Concentration available:
Explain how the researcher could use her raw data to find the mode and range?
Mode: (Find) the most common result;
Range: Highest and lowest result;
When would you use the MEDIAN value?
Small sample with anomolous data at one extreme
