The mean of n numbers is the sum of the numbers divided by n.
You have a mean score of 84 after taking 5 tests. Let x be the sum of scores.

You scored a total of 420 points on five tests.
You need to have a mean score of 85 after taking 6 tests. Let y be the score you need to obtain. Your total score on 6 tests is 420+y.

You need to score 90 points on the sixth test.
Step-by-step explanation:
Remember:
SOH - Sin(angle) = Opposite/Hypotenuse
CAH - Cos(angle) = Adjacent/Hypotenuse
TOA - Tan(angle) = Opposite/Adjacent
Answer:
12 dimes, 8 nickels
Step-by-step explanation:
1. Set up an equation. Since we know the relationship between how many dimes and how many nickels that he has, we can create values for them.
2. Say that the number of nickels is x, so the number of dimes would be 2x-4.
3. Since we know that all of the coins that he has is 20 coins, we can say that 2x-4+x=20.
4. Solve the equation. We get 3x=24, and x=8.
5. That means that the number of nickels is 8, and the number of dimes is 2(8)-4, which is 12.
Answer: Timmy has 12 dimes and 8 nickels.
This sine function has the form y = f(x) = a sin (bx + c), where |a| is the amplitude, b is the frequency, and c determines the phase shift.
The period of this sine curve is 2 pi/b, or (in this problem) 2 pi/(1/2).
The phase shift of this curve is -c/b, or -(pi/4)/(1/2). Simplify this.
The amplitude is |-3|, or just 3.
Draw a set of coordinate axes. Draw light horizontal lines through y=3 and y=-3. These are the max and min. values of this sine function.
Plot the phase shift on your x-axis.
Your sine function will begin at (phase shift value, 0) and continue for one period. Add the period to the phase shift value. Draw a sine curve beginning and ending at these two x-values.
I encourage you to share your calculations and to sketch the graph described here. Then I could give you more specific feedback on your work. Good luck!
9.4 - 1.8 will tell you the distance between them