Note :- If sample size n > 30 OR Population standard deviation σ is given then We use Z test.
If sample size n < 30 AND Population standard deviation σ is unknown then we use t test.
In this question we are not given Population standard deviations σ1 and σ2.
Also n1 = 14 and n2 = 13 both sample sizes are LESS than 30.
Therefore we use t test.
Given :- Assume the population standard deviations are equal. ( σ1 = σ2)
then Degrees of freedom = n1 + n2 - 2 = 14 + 13 - 2 = 25.
(kindly find the image attached with this solution)
Answer :- Therefore 25 degrees of freedom are used to find the t critical value.
No because the sum could also be irrational number which for example it could be square root of 9 or 49
Hope this helps answer your question
Hello!!
Well, the x-intercept is found when y = 0, so plug in y = 0:
-7x + 3(0) = 21
-7x = 21
x = -3
Therefore, the x-intercept of -7x + 3y = 21 is -3.
Hope this helps!! Let me know if you have ANY questions.
The equation which represents the amount of money, y, that Lilia will save in x weeks is;
<h3>Slope-intercept form of linear equations</h3>
The slope-intercept form of linear equations usually takes the form;
According to the information given;
Therefore, the y-intercept of the equation is; $10.
- And since she saves $5 each week;
The slope of the equation is; $5.
By substitution, the required equation is;
Read more on slope-intercept form of equations;
brainly.com/question/1884491
