Participants in a study were asked to scoop ice cream for themselves but half of them were given a large bowl and the other half were given smaller bowls. The sample of 85 participants given the large bowl served themselves 5.07 oz of ice cream on average and the 85 participants given the small bowl served themselves 4.38 oz on average. What's the 95% confidence interval that estimates the difference between the mean serving sizes (in oz). Assume t = 1.9817 and SE = 0.06. Do not round.

The answer is supposed to be as follows:

95% CI (0.808902, -0.571098)

How do you get the above answer? Please show your work. Thanks!