First, find the mean. You'll need it to compute the variance.

The variance of the sample is then computed with the formula

The standard deviation is the square root of the variance, so
Answer:
6
Step-by-step explanation:
-4x -3 = -6x +9
-4x = -6x +12
2X = 12
x = 6
125 would be the correct answer unless you needed to round then it would be 126
1st = 100% - 20% = 80%
2nd= 100%-15% = 85%
Net Price Factor = 0.8 x 0.85 = 0.68
Net Price = $1899 x 0.68
Final Net Price = $1,291.32
Total Discount= $1899 - 1,291.32 = $607.68
She purchased 4 children’s tickets. To solve you find out that she buys 3 adult tickets worth $27. Then add $4 until $43.