Dan's dinner cost $80.40. There was also a 7.5% tax on the dinner. What was the total cost of the dinner? PLZ HELP

True or false? a triangle can be circumscribed about a given circle

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

Find the exact value of each of the following. in each case, show your work and explain the steps you take to find the value. (a) sin 17π/6 (b) tan 13π/4 (c) sec 11π/3