Data And Distributions

Question 1

4 plants total: 2 are treated with water, 2 are in treated
Two leaves are taken from each plant and tests are performed on these.

How many independent data points are there in this experiment?

Answer 1

4

Question 2

4 plants total: 2 are treated with water, 2 are in treated
Two leaves are taken from each plant and tests are performed on these.

What type of replicates are the individual leaves?

Answer 2

Technical replicates

Question 3

What does n stand for?

Answer 3

Number of individual data points

Question 4

What is another name for the variance?

Answer 4

Mean square

Question 5

What is the numerator of the variance equation?

Answer 5

Sum of squares

Question 6

What is the denominator of the variance equation?

Answer 6

Degrees of freedom

Question 7

What are the degrees of freedom?

Answer 7

n-1

Question 8

If all but one of the data points are known and the mean is also known. How many places can the final data take?

Answer 8

Only one if the mean and all but one of the data points are known the final one can only take one fixed value. This is what the degrees of freedom means.

Question 9

What are the key features of a normal distribution?

Answer 9

1) Continuous
2) Bell shaped
3) Defined by the mean and standard deviation

Question 10

What is the normal distribution defined by?

Answer 10

1) it’s mean

2) it’s standard deviation

Question 11

What types of data are normally distributed?

Answer 11

1) Means of samples of random variables
2) Quantiles that are the sum of many independent processes
3) Things that you measure on a continuous scale

Question 12

95% of a normal distribution is found between how many standard deviations from the mean?

Answer 12

1.96

Question 13

What are the key features of a Poisson distribution?

Answer 13

1) Discrete
2) Right skewed for low means
3) Defined by the mean
4) The mean = variance

Question 14

What type of data usually follows a Poisson distribution?

Answer 14

Counts of independently occuring events in homogeneous units.

Question 15

What do you need to k ow to define a Poisson distribution?

Answer 15

Just the mean

Question 16

What are the key features of a binomial distribution?

Answer 16

1) Discrete

2) Defined by number of trials and probability of two possible events happening

Question 17

What follows a binomial distribution?

Answer 17

1)Counts of successes versus failures out of a fixed number of trials (where the probability of success is constant).

Question 18

What do you need to define a binomial distribution?

Answer 18

1) N (number of trials)

2) P ( probability of success in a given trial

Question 19

What is the 95% confidence interval for a parameter?

Answer 19

The confidence interval that will contain the true value of that parameter 95% of the time.

Question 20

What is the standard deviation of a sampling distribution of the mean called?

Answer 20

The standard error

Question 21

What is the standard error?

Answer 21

This is the standard deviation of the sampling distribution of the mean.

Question 22

What is the equation of the standard error?

Answer 22

Standard deviation/root of the number of independent data points

Question 23

What is the t distribution used for?

Answer 23

This is used to determine how wide the confidence interval needs to be depending on the number of independent data points

Question 24

What is the equation for CI

Answer 24

Mean +- tcrit x (SD/root n)