Lecture 2

Question 1

what are the measures of tendencies

Answer 1

-Mean
-Mode
-Median

Question 2

Mean- Define, how to calculate

Answer 2

Definition: the average value of the set.
How to calculate: add up all samples then divide by sample size. (amount of samples)

Question 3

Explain variation with sample size (N). (Mean)

Answer 3

Variation with sample size: as sample size increases it gets closer to the population mean

Question 4

Median define and calculate

Answer 4

Definition: is the number in middle of the sample (ranked in order)
How to calculate: The middle sample when the samples are ranked in order. (if there are two middle numbers add them then divide by 2)

Question 5

Explain variation with sample size (N). (median)

Answer 5

Variation with sample size: as sample size increases it gets closer to the population median

Question 6

Mode define and how to calculate

Answer 6

Definition: the the most repeated or frequent number that appears
How to calculate: find the most repeated value.

Question 7

Explain variation with sample size (N).(Mode)

Answer 7

Variation with sample size: as sample size increases it gets closer to the population mode

Question 8

what are the measures of dispersion?

Answer 8

-Range
-Interquartile range
- Standard error (SE)
-Standard deviation (SD)
- coefficient of variation (CV)

Question 9

Define and how to calculate Range

Answer 9

Definition: the Max to min value
How to calculate: Maximum value - Minimum value

Question 10

Explain variation with sample size (N). (Range)

Answer 10

Variation with sample size: as sample size increases it gets closer to the population range

Question 11

explain variation with magnitude of the mean (μ) (Range)

Answer 11

Variation with magnitude of the mean (μ) : larger magnitude with higher mean
Note:a larger range with a higher mean indicates that the data points are spread further apart from each other, even though the central tendency (represented by the mean) is shifted towards a higher value

Question 12

Define and calculate interquartile range

Answer 12

Definition: first to third quartile
Calculation: median of the lower half of the data (Q1) - median of the upper half of the data (Q3)

Question 13

Variation with sample size (Interquartile range-IQR)

Answer 13

Variation with sample size: as sample size increases it gets closer to the populations IQR

Question 14

Variation with magnitude of mean (μ)
(IQR)

Answer 14

Variation with magnitude of mean (μ): larger magnitude with higher mean Note: it tells you how much variation exists within the middle half of your data,

Question 15

Standard deviation (SD) define and what does it indicate for a data set?

Answer 15

Definition: The average distance to the mean.
Indicates how much variation exists within a dataset; a low standard deviation means data points are close to the mean, while a high standard deviation means data points are spread further from the mean.

Question 16

Left skewed distributions

Answer 16

the peak is on the right and it has a long tail on the left.
mean<median<mode (on x-axis)

Question 17

Symmetrical distribution

Answer 17

left and right sides mirror each other
mean=median=mode

Question 18

right skewed/Poisson distribution

Answer 18

the peak is on the left side and has a tail on the right .
mean>median>mode (on the x)

Question 19

Uniform distribution

Answer 19

a probability distribution where all possible outcomes are equally likely

Question 20

Bimodal distribution

Answer 20

a type of probability distribution that exhibits two distinct peaks indicating the presence of two separate groups within the same dataset.

Question 21

Multimodal

Answer 21

Has more than two peaks on a graph, indicating multiple clusters or distinct groups within the data.

Question 22

Standard error

Answer 22

a measure of the statistical accuracy of an estimate. The expected average difference between your sample
mean and the population mean.

Question 23

Which of the 3 measures of dispersion is negatively related to sample size?
(smaller dispersion for larger sample sizes)

Answer 23

Standard error

Question 24

which of the measures of dispersion does not get bigger when when the mean of the sample size gets bigger?

Answer 24

Coefficient of variation (CV)

Question 25

Coefficient of variation

Answer 25

The SD controlling for the size of the mean; or the SD of
the sample if it’s mean were 1.0