Question

1. Publicly-available data can be obtained through

a. formal request and/or having the appropriate connections.

b. personally conducting a survey asking people for information and recording their responses.

c. the internet or through formal Freedom of Information Act (FOIA) requests from the appropriate agency.

d. obtaining data from your work that cannot be shared with other individuals.

2. The standard deviation of a distribution provides a sense of

a.		how far data points tend to fall from the median.
b.		where the central mass of the distribution lies.
c.		how far data points tend to fall from the mean.
d.		whether the distribution is skewed.

3. The unexplained variation in y is

a.		the distance between the observed and predicted values of y.
b.		the distance between the mean and the best-fit line.
c.		the distance between the mean and the data points.
d.		the distance between the mean and the predicted value of y.

THANK YOU !! Please also exaplain the answer.

Answer 1

1. Publicly available data can be obtained through c) internet or through FOIA requests from appropriate agency as it is available for everyone to be used.

Any public available data do not require permission to access the data as it is publicly available so a) is incorrect. As data is available already so no need to personal conduct surveys again so b) is incorrect. Public available data can be shared with anyone but data from you work cannot be shared with other individuals so d) is incorrect.

2. Standard deviation is used to quantify the variation in data set from the mean. so c is correct.

a is incorrect as mean and median are different and median is middle most value and does not consider extreme values whereas mean take extreme values to. c is incorrect as standard deviation does not tell where central mass lies. d is incorrect as skewness tell whether distribution is skewed or not.

3. The unexplained variation is Y is the distance between the observed and predicted values of y as can not explain relation between X and Y and due to other variables.

c) the distance between the mean and the data points tells total variation = explained + unexplained variation

d) the distance between the mean and the predicted value of y tells explained variation which tell relationship between x and Y