Physics and Math Chapter 12: Data-based and Statistical Reasoning

Question 1

Measurements of central tendency

Answer 1

provide a single value representation for the middle of a group of data.

Question 2

Arithmetic mean or average

Answer 2

measure of central tendency that equally weighs all values; most affected by outliers.

Question 3

Median

Answer 3

Value that lies in the middle of the data set. 50% of points are above and below the median

Question 4

Mode

Answer 4

the data point that appears most often; there may be multiple (or zero) modes in a data set

Question 5

Distributions

Answer 5

have characteristic features that are exemplified by their shape. Distributions can be classified by measures of central tendency and measures of distribution.

Question 6

Normal distribution

Answer 6

symmetrical - mean, median and mode are all the same in the normal distribution.
- 68% of points occur within one standard deciation of the mean, 95% within 2 and 99% within 3.

Question 7

Standard normal distribution

Answer 7

normal distribution with a mean of 0 and a standard deviation of 1; used for most calculations

Question 8

Skewed distributions

Answer 8

have differences in their mean, median and mode; the skew direction is the direction of the tail of the distribution

Question 9

Bimodal distributions

Answer 9

have multiple peaks, although not necessarily multiple modes, strictly speaking. It may be useful to perform data analysis on the two groups separately.

Question 10

Range

Answer 10

the difference between the larges and smallest values in a data set

Question 11

Interquartile range

Answer 11

the difference between the value of the third quartile and first quartile 0 interquartile range can be used to determine outliers

Question 12

Standard deviation

Answer 12

a measurement of variability about the mean; can also be used to determine outliers.

Question 13

Outliers may be a result of:

Answer 13

true population variability, measurement error or a non-normal distribution

Question 14

Prob of Independent Events

Answer 14

Does not change based on the outcomes of other events

Question 15

Mutually exclusive outcomes

Answer 15

cannot occur simultaneously

Question 16

Hypothesis tests

Answer 16

known distribution to determine whether a hypothesis of no difference (the null hypothesis) can be rejected.

Question 17

p-value

Answer 17

determines whether or not a finding is statistically significant at a specific significance level. - generally sl = 0.05

Question 18

Confidence intervals

Answer 18

a range of values about a sample mean that are used to estimate the population mean. A wider interval is associate with a higher confidence level.