The average of four numbers is 85. If three of the numbers are 76, 78, and 81, what is the fourth number?

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).

In the field of thermodynamics, rankine is the unit used to measure temperature. one can convert temperature from celsius into rankine using the formula , what is the temperature in celsius corresponding to r degrees rankine? a. 9/5(c - 273) b. 9/5(c + 273) c. 5/9( c - 273) d. 5/9( c + 273)

Fiona has to plot a histogram of the given data