sorry to title that like a weird job ad but I'm desperate. I've redone this Simpson's diversity index five different times now in different ways with different calculators and I keep getting a negative number which. from my understanding isn't possible??
^ My data (rough edition, I'll rename shit properly later)
^ My equation
I have no idea what I'm doing wrong and as it is the summer holiday while I am just trying to start my bio IA, I do not have any teacher and google is simply unhelpful other than telling me there is no negative possibility for a diversity percentage. I ??? help
Do you have tips for studying maths?? I love your blog :D
I wish I could help you out but unfortunately I did not take maths after 10th, and how I studied it before is too.. *flashbacks to solving maths with tears on the page* sad for me to remember.
Anyway, I'm putting this out, please anyone with tips help a fellow out.
In all seriousness if someone could please explain to me the concepts of differentiation and integration at A-Level level, with how to use the different rules and stuff (chain, quotient, product and the other two I can’t remember) that would be great please
Or if you can point me in the direction of someone or something that can ❤️
wild question but does anyone here understand maths
alright clearly i don’t understand dimensions and fundamental/derived SI units. can’t believe i’m posting about fucking maths but i was there for the whole fucking 3 hour lecture and i THOUGHT i understood but the more i think about it the more confused i become. i’m supposed to show how i got the dimensions for viscosity and they gave me some equations to help but i legit don’t get it. i’ve googled the process and i still don’t get it.
why the fuck am i in STEM i wanted to write stories lmfao clearly this maths is easy and i’m just not getting it hdgsjfagh
Population- The set of all things that you are interested in.
Sample- A subset of the population.
Parameter- A numerical measure of a population (e.g. mean/ standard deviation).
Statistic- A numerical measure of a single sample; one or more statistics can be used to estimate the population.
Biased- If the resulting sample is not representative of the population.
(Question) “Give a reason why this sample is not a random sample.”
(Answer) Not all subsets are possible.
Simple Random:
Method:
Assign a number to each member of the population using a full list of the population.
Generate a list of random numbers using a random number generator.
Choose the corresponding members for your sample.
Ignore any repeats/ numbers outside the range.
Positives:
Every member of the population has an equal chance of being selected - so this method is completely unbiased.
Negatives:
May be inconvenient if the population is spread over a large area (as it would be difficult to locate & contact the selected members).
Stratified:
Method:
Divide the population into categories (called ‘strata’).
Calculate the total population.
Calculate the number needed for each category in the sample using:
4. Select the sample for each category using the simple random sampling method.
Positives:
Useful when results may vary depending on the strata.
Representative (if the population has clearly distinct categories).
Negatives:
May be inconvenient if the population is spread over a large area (as it would be difficult to locate & contact the selected members).
Systematic:
Method:
Assign a number to each member of the population using a full list of the population.
Calculate a regular interval to use by dividing the population size by the sample size.
Generate a random starting point that is less than or equal to the size of the interval. The corresponding member of the population is the first member of the sample.
Continue adding the interval to the starting point to select the remaining sample members.
Positives:
This method can be used for quality control on a production line.
Should give an unbiased sample.
Negatives:
Regular intervals may coincide with a pattern.
Cluster:
Method:
Split the population into clusters that you expect to be similar to each other.
Take a sample from some of these clusters at random.
Positives:
Quick and economic/inexpensive to gather a sample.
Negatives:
Not representative of the population.
More likely to be a biased sample.
REMEMBER: Categories/Strata are groups that you expect to be different (e.g. year groups in school) but Clusters are groups you expect to be similar (e.g. different classes in the same year group).
Opportunity:
Method:
The sample is chosen from a section of the population that is convenient for the sampler.
Positives:
Very quick.
Very easy.
Negatives:
Not random so very biased (no attempt to make it representative).
Quota:
Method:
Divide the population into categories.
Give each category a quota (number of members to sample).
Collect data until the quotas are met in all categories without using random sampling (usually opportunity).
Positives:
Interviewer continues until quotas are met so non-response is less of a problem.
Does not require a full list of the population.
Negatives:
Can be easily biased by the interviewer.
Not a random sample.
Avoid sample bias by:
Randomly selecting a sample.
Ensure all sample members respond.
Select from correct population & include everyone.
