Recent research suggests that depression significantly increases the risk of developing dementia later in life (BBC News, July 6, 2010). In a study involving 949 elderly persons, it was reported that 22% of those who had depression went on to develop dementia, compared to only 17% of those who did not have depression.a. Choose the relevant population and the sample. (You may select more than one answer. Bold the answer(s) that are correct.)i. The sample consists of all elderly people.ii. The sample consists of 949 elderly people.iii. The population is all younger and elderly people.iv. The population is all elderly people.b. Do the numbers 22% and 17% represent the population parameters or the sample statistics? Bold the answer that is correct.i. Population parametersii.Sample Statistics

Answer:

n=6

"=T.INV(1-0.025,5)", and we got the critical values given by:  

n=12

"=T.INV(1-0.025,11)", and we got the critical values given by:  

Step-by-step explanation:

Previous concepts

The t distribution (Student’s t-distribution) is a "probability distribution that is used to estimate population parameters when the sample size is small (n<30) or when the population variance is unknown".

The shape of the t distribution is determined by its degrees of freedom and when the degrees of freedom increase the t distirbution becomes a normal distribution approximately.  

The degrees of freedom represent "the number of independent observations in a set of data. For example if we estimate a mean score from a single sample, the number of independent observations would be equal to the sample size minus one."

Solution to the problem

For n=6

In order to find the critical value we need to take in count that we are conducting a two tailed test, so we are looking on the t distribution with df=n-1=6-1=5 degrees of freedom, a value that accumulates of the area on each tail. We can use excel or a table to find it, for example the code in Excel is:  

"=T.INV(1-0.025,5)", and we got the critical values given by:  

For n=12  

In order to find the critical value we need to take in count that we are conducting a two tailed test, so we are looking on the t distribution with df=n-1=12-1=11 degrees of freedom, a value that accumulates of the area on each tail. We can use excel or a table to find it, for example the code in Excel is:  

"=T.INV(1-0.025,11)", and we got the critical values given by:  

Answer:

5

Step-by-step explanation:   c on edg

Answer: c=5

Step-by-step explanation:

C on edg got 100%

Answer:

5x=54

Step-by-step explanation:

5x=54

divide 5 by both sides

x=10.8

sorry if I am wrong but I tried my best

Answer: 44

Step-by-step explanation: