A) The first step needs 100 bricks, the second needs 98, the third needs 96, and so on. Therefore the number of bricks for the nth step is: a_n = a_1 + d(n-1), where a_1 = 100 (the first term), d = -2 (difference).
a_n = 100 - 2(n-1) = 102 - 2n, and for the 30th step, a_30 = 102 - 2*30 = 42. So the top step will need 42 bricks.
b) The total staircase will need: 100 + 98 + 96 + ... + 44 + 42, and there are n = 30 terms. Using the formula for the sum of an arithmetic sequence:
S = (a_1 + a_n)*n/2 = (100 + 42)*30/2 = 2130
Therefore, 2130 bricks are required to build the entire staircase.
Are there any more numbers to this problem ? a picture of the data
The answer is sixty!
4(5+10)
4(15)
60
Answer:
-11-12h
Step-by-step explanation:
Answer:
Option B. Standard error of predicted amount.
Step-by-step explanation:
A standard error predicted amount will work best in this scenario. The data, when extracted from the standard mean, provides the most accurate presentation of the statistical data on question. By using the standard error, the variation from the central point can be determined.
