Biostatistics III

Question 1

what type of event is the following example?

Consider flipping a fair coin 10 times, the sequence could be (“H” indicates head, “T” indicates tail).

Answer 1

random event

Question 2

what type of variable is the following example?

Random event: to flip a fair coin 10 times
Outcomes of the random event: sequences we could possibly observe by flipping a fair coin 10 times
Possible measurements of the above outcomes?

Answer 2

random variable

Question 3

the following types are examples of?

Categorical (Nominal/Ordinal)
Discrete
Continuous

Answer 3

Variable

Question 4

the following types are examples of?

Discrete
Continuous

Answer 4

Random Variable (RV)

Question 5

when we flip a fair coin 10 times, RV1 is defined as the number of heads in the sequence (denoted by X) and RV2 is the number of tails in the sequence (denoted by Y). Suppose the event of interest is we observe 5 heads in the sequence, that is equal to X=5 or Y=5.

what is this an example of?

Answer 5

event

Notation: A, B, C, etc.

Question 6

We wanted to know what is the chance of observing 5 heads in the sequence, that is equal to ask what is Probability(A) (=P(A)=P(X=5)=P(Y=5))

what is this an example of?

Answer 6

probability

Notation: Probability (A) or P (A)

Question 7

X denotes the number of heads in the sequence when we flip a fair coin 4 times, the probability distribution could be displayed either by a table or a distribution plot

what is this an example of?

Answer 7

probability distribution, discrete random variable

Question 8

Children’s IQ scores are normally distributed with a mean of 100 and a standard deviation of 15.
Normal distribution

what is this an example of?

Answer 8

probability distribution, continuous random variable

Question 9

A large number of statistical tests and calculations can be used if the test statistic follows this _____?

Answer 9

normal distribution

Question 10

when the mean=mode=median, what type of distribution is this?

Answer 10

normal distribution

Question 11

the following properties describe what type of distribution?

shape
support
parameters
notation
special cases

Answer 11

normal distribution

Question 12

this type of distribution is important for continuous RVs?

Answer 12

t distribution

Question 13

the following properties describe what type of distribution?

shape
support
parameter

Answer 13

t distribution

Question 14

what is the basic definition for degrees of freedom?

Answer 14

the freedom to vary

Question 15

the following is an example of?

wearing hats with constraints_ 7 hats and needs to wear differently every day of the week and so you only have a certain amount of flexibility

Answer 15

degrees of freedom

Question 16

this the parameter for certain distributions (such as t, F, and chi-square distribution)

Answer 16

Degrees of freedom

Question 17

this is a model used to model the number of successes among n trials when the following requirements are met:

1) Only two outcomes for each trial, generally labeled “Success” and “Failure”;
2) n is fixed;
3) Trials are independent;
4) p-the probability of “success” is constant from trial to trial.

Answer 17

Binomial Distribution

Question 18

what are the properties that define binomial distribution?

Answer 18

shape
support
parameters
notation
special cases