How do I incorporate these 2 and peer respond: Good afternoon class and professor, This week was challenging because I had to seek additional resources on YouTube and reread my classmate's posts numerous times. To calculate the T-critical value we will use the =T.INV( ) function in Excel. For a 95% confidence interval, you will take 1 - .95 = .05. = .05. But since this is a confidence interval and we will need to add AND subtract from the mean we will take .05/2 = .025. The new = .025. But remember how Excel puts functions in a less-than-form. To find the value we will use in the Excel function we will take 1 - .025 = .975. Mean: $17,554 SD: 10203.85368 T-critical Value: 2.262157163 =T.INV(0.975,9) The upper limit is: =17554+2.262157163*(10203.85368/SQRT(10)) =$24,853 The lower limit is: =17554-2.262157163*(10203.85368/SQRT(10)) =$10,254 I am 95% confidence that the population mean car price for the type of cars from week 1 is between $24,853 and $10,254 We use the same process to calculate the Z-critical. = 1 - .95 = .05. We still need to calculate for a interval since we are adding and subtracting from the mean, so we take the =.05 /2= 0.25. Since Excel uses less than form we have to use the following formula 1-.025 = .975, this is our new =.975. we input in the function =NORM.S.INV(.975) Z-Critical: 1.959963986 =NORM.S.INV(0.975) P=.5 Q=.5 The upper limit is: =0.5+1.959963986*(SQRT(0.5*0.5/10)) =80.99% The lower limit is: =0.5-1.959963986*(SQRT(0.5*0.5/10)) =19.01% I am 95% confidence that the population proportion of cars prices will fall below the average is between 19% and 81%. https://youtu.be/sxynstFx39E?si=cRUoGqyeJCvLvGlH Respectfully, Ramirez, Lily In your first peer posts, pick another confidence level, i.e. 90%, 99%, 97%, any other confidence level is fine. Have fun and be creative with it and calculate another T-confidence interval and interpret your results. Compare your results to that of the initial 95%, how much do they differ? How useful can this type of information be when you go to buy a new car, or even a house