Answer:
z=5
Step-by-step explanation:
12.2z+ 19.4 = -2.7z + 93.9
14.9z=74.5
z=5
Answer:
The difference of squares is (a - b)(a + b) = a² - b². Since a = x and b = 2, the answer is x² - 4.
Counting each visible cube, and multiplying it by 2, he used 112. If you counted them, there would be 56 cubes. You'd multiply by 2 for the non-visible ones.
The proportion of buses traveling more than 900 miles would be 0.0485; multiply this by the total number of buses and you will have your answer.
We find the z-score associated with 900 miles:
z = (X - μ)/σ = (900-830.11)/42.19 = 1.66
Using a z-table (http://www.z-table.com) we see that the area under the curve to the left of this, less than this, is 0.9515. This means that the area under the curve to the right of this, greater than this, would be 1-0.9515 = 0.0485.
