A sociologist is studying the social media habits of high school students in a school district. The sociologist wants to estimate the average total number of minutes spent on social media per day in the population. A random sample of 50 high school students was selected, and they were asked, “How many minutes per day, on average, do you spend visiting social media sites?"

Which of the following is the most appropriate inference procedure for the sociologist to use?

A one-sample z-interval for a population proportion

A

A one-sample t-interval for a population mean

B

A matched-pairs t -interval for a mean difference

C

A two-sample z-interval for a difference between proportions

D

A two-sample t-interval for a difference between means

A one-sample t-interval for a population mean

Step-by-step explanation:

As the question is "How many minutes per day, on average, do you spend visiting social media sites?", the answer will be in a numerical form (number of hours, positive integer or real number).

As this is not a proportion, the option "A one-sample t-interval for a population mean" is discarded.

As the study does not defined another variable to compare in pairs, it is not a matched-pairs test. Option "A matched-pairs t -interval for a mean difference" discarded.

There are not two means in the study, so there is no "difference between means" variable. Options "A two-sample z-interval for a difference between proportions" and "A two-sample t-interval for a difference between means".

This should be a  one-sample t-interval for a population mean, as there is only one sample, one population mean and the population standard deviation is not known.

step-by-step explanation:

given that there are two triangles j'k'l' and jkl>

the former is got by dilating the second one.

when drawn on a grid, (graph paper) coordinates of vertices of first triangle is

(6,12)j, (9,6)k and (12,9)l

side jk has length = distance between j and k

=

side j'k'=distance between j' and k'

=

ie j'k'l' has sides 1/3 of that of corresponding sides of jkl.

hence scale factor of 1/3 is used to get j'k'l'from jkl