Thirty three different video games showing violence were observed. The duration times of violence (in seconds) were recorded. When using this sample for a t test of the claim that the population mean is greater than 72 sec, what does df denote, and what is its value?

The "df" stands for "degrees of freedom", and represents the number of independent observations in a set of data.

Its value in this case is df=32.

Step-by-step explanation:

The sample is of size n=33.

As we do not know the population's standard deviation, we use as estimate the sample's standard deviation. Because of this, we use the t-statistic in place of the z-value.

The "df" stands for "degrees of freedom", and represents the number of independent observations in a set of data (the data in this case is the sample of 33 video games).

In one-sample tests, the degrees of freedom are calculated as:

option 1 is correct.

step-by-step explanation:

y varies inversely with x and constant of variation is 4

the equation will be:

y = k/x

where k =4 so,

y = 4/x

if we put values of x of option 1 in the above equation and find values of y

y = 4/-2 => y =-2

y = 4/-1 => y = -4

y = 4/1 => y = 4

y = 4/2 => y =2

so, all the values of x and y are correct.

if we put values of x given in other options and find value of y we cannot find whole table satisfying the equation.

hence option 1 is correct.