The total number of combinations is 2,560.
To find the total, we need to use the number of options for all 4 of the categories. Once we have those number, we just need to multiply them to find the total number of possibilities. This is called the Fundamental Counting Principle.
8 x 8 x 8 x 5 = 2560
<span>7x-4y=-7
5x+y=22
multiply 4 on the 2nd equation
</span>20x+ 4y=88
now you have
7x -4y = -7
20x + 4y = 88
--------------------add
27x = 81
x = 3
7x-4y=-7
7(3)-4y=-7
-4y = -28
y = 7
answer (3, 7) is the solution
The <em><u>correct answer</u></em> is:
We can conclude that 68% of the scores were between 55 and 85; 95% of the scores were between 40 and 100; and 99.7% of the scores were between 25 and 100.
Explanation:
The empirical rule tells us that in a normal curve, 68% of data lie within 1 standard deviation of the mean; 95% of data lie within 2 standard deviations of the mean; and 99.7% of data lie within 3 standard deviations of the mean.
The mean is 70 and the standard deviation is 15. This means 1 standard deviation below the mean is 70-15 = 55 and one standard deviation above the mean is 70+15 = 85. 68% of data will fall between these two scores.
2 standard deviations below the mean is 70-15(2) = 40 and two standard deviations above the mean is 70+15(2) = 100. 95% of data will fall between these two scores.
3 standard deviations below the mean is 70-15(3) = 25 and three standard deviations above the mean is 70+15(3) = 115. However, a student cannot score above 100%; this means 99.7% of data fall between 25 and 100.
Answer:
110
Step-by-step explanation:
you place 30 in the place of X, and it becomes 4×30-10. in PEMDAS, multiplication goes first and 4×30=120. 120-10=110