Decide weather descriptive or inferential statistics is used: a) The age of students in cs340 course is between 19 and 55. b) Next year 100 students will enroll in BUS310. c) The use of the recent data will result in more accurate results. d) Smoking will increase the risk of having emphysema. e) Their presentation gave us a better understanding of how cats behave. Solution a.descriptive b.inferential statistics c.inferential statistics d.inferential statistics e.descriptive.

1. Decide whether each in?nite geometric series diverges or converges. State
whether each series has a sum.
1.3+3/2+3/4 ... 2. 4 + 2 + 1 + ... 3. 17 + 15.3 + 13.77 + ...
4. 6 + 11.4 + 21.66 + ... 5. -20 - 8 - 3.2 - ... 6. 50 + 70 + 98 + ...
Evaluate each in?nite geometric series.
11. 8 + 4 + 2 + 1 + ... 12.1+1/3+1/9+1/27 ...
13. 120 + 96 + 76.8 + 61.44 + ... 14. 1000 + 750 + 562.5 + 421.875 + ...
Determine whether each series is arithmetic or geometric.Then evaluate the
series to the given term.
15. 2 + 5 + 8 + 11 + ...; S9 16.1/8+1/16+1/32+1/64 ...; S8
17. -3 + 6 - 12 + 24 - ...; S10 18. -2 + 2 + 6 + 10 + ...; S12
Evaluate the ?nite series for the speci?ed number of terms.
19. 40 + 20 + 10 + ...; n = 10 20. 4 + 12 + 36 + ...; n = 15
21. 15 + 12 + 9.6 + ...; n = 40 22. 27 + 9 + 3 + ...; n = 100
23. 0.2 + 0.02 + 0.002 + ...; n = 8 24. 100 + 200 + 400 + ...; n = 6
25. This month, Julia deposits $400 to save for a vacation. She plans to
deposit 10% more each successive month for the next 11 months.
How much will she have saved after the 12 deposits?
26. Suppose your business made a pro?t of $5500 the ?rst year. If the
pro?t increases 20% per year, ?nd the total pro?t over the ?rst 5 yr.
27. The end of a pendulum travels 50 cm on its ?rst swing. Each swing
after the ?rst travels 99% as far as the preceding one. How far will the
pendulum travel before it stops?
28. A seashell has chambers that are each 0.82 times the length of the next
chamber. The outer chamber is 32 mm around. Find the total length of
the shell
Solution
28) a = 32 mm , r = 0.82 and if we take the sum for infinite series, we can get the total length of
shell's chambers
so total length = 32 / (1-0.82) = 177.78 mm
29) a = 495000, r = 1-0.1 = 0.9, n =6
so sum = a (1 - r^n) / (1 - r) and we get: sum = $ 2319367