Help needed, I can't figure out the correct answer.

4) In a study of the impact of carbon dioxide on plant growth, botanist grew pine seedlins under two concentrations of CO2: 417ppm and 834ppm. The CO2 concentration of 417 ppm is the Earth's current CO2 concentration as of May, 2020. A comparison of the current CO2 and a doubled concentration was thought to reveal any significant difference in plant growth. Two green houses were set up to hold the concentrations of CO2 while temperature and watering regimens remained constant. 39 pine seedlings were grown in the first green house under 417ppm CO2 concentration and 37 pine seedlings were grown in the second green house under 834ppm CO2 concentration. The botanist claim that the the seedlings subjected to higher CO2 levels will grow more as indicated by the mean seedling height in inches after 4 months. The experiment returned a mean and standard deviation of 24.1 and 6.9 inches for the seedlins grown at 417ppm CO2 concentration respectively, while the pine seedlings grown at the higher concentration of 834 ppm CO2 had a mean and standard deviation of 30.2 and 7.8 inches respectively. Determine whether there is evidence that seedlings grown in higher concentrations of CO2 result in taller plants by running an appropriate hypothesis test at a 1% LOS. 4a) Step 1: Preliminary Checks: 4b) Step Declare the variables for this hypothesis test: 4c) Step 3: Write a complete hypothesis statement to test the claim that pine seedlings grown at higher CO2 concentrations will result in greater growth. Test the hypothesis at a 1% LOS. . 4d) Step 4: Find the Critical value and place it upon the decision line for this hypothesis. 4e) Step 5: Write a complete statistical conclusion for this hypothesis test. A comparison of the sample value to the critical value with respective notation should be displayed along with a bracketed p-value compared against an LOS, all with correct notation. 4f) Step 6: Write an English sentence conclusion for this hypothesis test. 4g) Find a 68% confidence interval on the difference of the mean height in inches between plants grown at 417ppm CO2 vs 834ppm CO2 environments