August 15, 2011
P. Martin Fenlon
Week One Written Assignment
For week one, we are assigned two problems from our readings. According to the assignment “complete exercises 35 and 37 in the “Real World Applications” section on page 230 of Mathematics in Our World.” My copy I obtained from the Electronic service VitalSource, which is provided by the Ashford library, is numbered differently, so I hope I got the correct problems. The page I found the problems on is numbered 280. The assignment also states “specify whether it involves an arithmetic sequence or a geometric sequence” and to do this I will first define what each sequence means. According to Bluman (2011), “An arithmetic sequence is a sequence of numbers in which each succeeding term differs from the preceding term by the same amount. This amount is known as the common difference.” (p. 262). An example of this would be counting by 2’s, going from 2 to 4 to 6. This differs from a geometric sequence which according to Bluman (2011), “is a sequence of terms in which each term after the first term is obtained by multiplying the preceding term by a nonzero number, This number is called the common ratio.” (p. 266). An example of this is seen in the sequence 2, 10, 50, 250, 1250 and the common ratio would be the number 5.
The first problem uses an arithmetic sequence to solve the problem.
35. A person hired a firm to build a CB radio tower. The firm charges $100 for labor for the first 10 feet. After that, the cost of the labor for each succeeding 10 feet is $25 more than the preceding 10 feet. That is, the next 10 feet will cost $125, the next 10 feet will cost $150, etc. How much will it cost to build a 90-foot tower?
Sn =a1 + (n−1) d n = 9 a1= 100 an= 25