Tell whether the ratios form a proportion. 21:3 and 16:6

Which of the following is the equation of a line that passes through the point (1,4) and is parallel to the x-axis a. y=1 b. y=4 c. x=1 d. x=4

The mean of a set of data is -3.82 and its standard deviation is 2.31. find the z score for a value of 3.99.

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