Question

The yearly rainfall for 8 towns are recorded in 2014 and 2015 (in inches). Yearly rainfall, 2014-2015 Rain in 2014 Rain in 2015 48.3" 50.1" 36.2" 35.1" 68.3" 64.2" 24.8" 29.1" 32.8" 38.3" 71.4" 68.5" 49.1" 53.8" 58.3" 51.9"

1. Calculate the mean difference. (Round your answer to the nearest thousandth)

2. Calculate the sample standard deviation. (Round your answer to the nearest thousandth)

3. A weather company is interested in seeing if the rainfall in 2015 is statistically different than the rainfall in 2015 at the 95% confidence level. What is the test to be done?

4. Find the test statistic to the nearest thousandth.

5. Find the p-value in the table for the table value of t closest to the calculated value of the test statistic.

Answer 1

Given Let da Rain in 2014 - Rain in 2015 2014 2015 d 4.8.3 Soul -108 36.2 35. 1 11 68.3 64.2 4.1 24.8 29. 1 -4.3 32.8 38.3 -5.5 71.4 68.5 49.1 53.8 -4.7. - 58.3 51.9 -108 n = 8 , {d=-1.8, {d2=141.46 - 0225. Sdr 5d? n aj2 141.46- 8X (-0,225) 2 sd a 4.489

I ③ sda 4.489 x 0.05 Here we test that Ho uda 0 vs paired t test Hir. Ud for 5) Under Ho. Test statistic is h . o.225 Sal5n 4.489158 = 0.14 to – 0.14 P-value = Plitness st) a D = P(tni lat)t Plturisti - 2x Pltni lati 2X PC ty <-0.142 - 2X 0.4463 = 0.8926 P-varueset Fait to rejection There is not enough evidance to conclude that the Rainfall in 2015 is statistically different from Rajn fun in 2014