Answer:
The 80% confidence interval for difference between two means is (0.85, 1.55).
Step-by-step explanation:
The (1 - <em>α</em>) % confidence interval for difference between two means is:

Given:

Confidence level = 80%

*Use a <em>t</em>-table for the critical value.
Compute the 80% confidence interval for difference between two means as follows:

Thus, the 80% confidence interval for difference between two means is (0.85, 1.55).
The decimal of 2.1 is greater than 2.0 but less than 2.42
Maybe use a Calculator and multiple the two number?
5p squared - 2p - 8 - 8 over p+3