Answer:
D
Step-by-step explanation:
an = 7 - 3(n - 1)
= 7 -3n - 1 *(-3)
= 7 - 3n + 3 {Combine like terms}
= 7 + 3 - 3n
= 10 - 3n
= -3n + 10
Answer:
17
Step-by-step explanation:
Initial marbles : 3+5+2+8 = 18
After taking blue marble out : 18 - 1 = 17
Find the mean ( average):
105 + 104 + 110 + 112 + 114 + 106 + 108 +109 = 868
Mean = 868 / 8 = 108.5
Standard deviation:
108.5 - 105 = 3.5, 3.5^2 = 12.25
108.5 - 104 = 4, 4^2 = 16
110 - 108.5 = 1.5, 1.5^2 = 2.25
112 - 108.5 = 3.5, 3.5^2 = 12.25
114 - 108.5 = 5.5, 5.5^2 = 30.25
108.5 - 106 = 2.5, 2.5^2 = 6.25
108.5 - 108 = 0.5, 0.5^2 = 0.25
109 - 108.5 = 0.5, 0.5^2 = 0.25
12.25 + 16 +2.25 + 12.25 + 30.25 +6.25+0.25+0.25 = 79.75
79.75/8 = 9.96875, SQRT(9.96875) = 3.1573
Standard Deviation = 3.1573
108.8 +/- 1.96 *(3.1573/sqrt(8) = 110.687 and 106.312
110.687 - 108.5 = 2.19
108.5 - 106.312 = 2.19
Margin of error = +/- 2.19
X+4+3x =
4x+4 (you sum the like terms )
If they give you the total price and the price after the discount you can use this "formula" to solve it p/100=b/a where p is the percentage, a is the total price and b is the price after the discount.
