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Concept explainers
. Exponential growth and decay laws. Consider the following cases of exponential growth and decay.
- Create an exponential function of the form \[Q = {Q_0} \times {(1 + r)^t}\] (where r >0 for growth and r <0 for decay) to model the situation described. Be sure to clearly identify both variables in your function.
- Create a table showing the value of the quantity Q for the first 10 units of time (either years, months, weeks, or hours) of growth or decay.
c. Make a graph of the exponential function.
29. A privately owned forest that had 1 million acres of old growth is being clear cut at a rate of 7% per year.
30. A town with a population of 10,000 loses residents at a rate of 0.3% per month because of a poor economy. 31. The average price of a home in a town was $175,000 in 2013, but some prices are rising by 5% per year.
32. A certain drug breaks down in the human body at a rate of 15% per hour. The initial amount of the drug in the bloodstream is 8 milligrams. 33. Your starting salary at a new Job is $2000 per month, and you get annual raises of 5% per year. 34. You hid 100,000 rubles in a mattress at the end of 1991, when they had a value of $10,000. However, the value of the ruble against the dollar then fell 50% per year.
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Chapter 9 Solutions
Using & Understanding Mathematics: A Quantitative Reasoning Approach (7th Edition)
- Students were asked to simplify the expression (secØ - cosØ)/secØ Two students' work is given.Student A: step 1 secØ/secØ - cosØ/secØstep 2 cosØ/1 - (1/cosØ)step 3 1 - cos^2Østep 4 sin^2ØStudent B: step 1 (1/cosØ)-cosØ)/secØstep 2 (1 - cos^2Ø/cosØ)/secØstep 3 sin^2Ø/cos^2Østep 4 tan^2ØPart A: Which student simplified the expression incorrectly? Explain the errors that were made or the formulas that were misused.Part B: Complete the student's solution correctly, beginning with the location of the error.arrow_forwardAlthough 330° is a special angle on the unit circle, Amar wanted to determine its coordinates using the sum and difference formulas.Part A: Determine cos 330° using the cosine sum identity. Be sure to include all necessary work.Part B: Determine sin 330° using the sine difference identity. Be sure to include all necessary work.arrow_forwardA public health researcher is studying the impacts of nudge marketing techniques on shoppers vegetablesarrow_forward
- 4. Let A {w, e, s, t, f, i, e, l, d, s, t, a, t, e}. (a) How many different words (they do not have to make sense) can you spell with the letters in A? (b) Is your answer from above the same as the cardinality of the powerset of A, i.e. of P(A)? (c) What is |A|?arrow_forwardwhat can the answer be pls helparrow_forward5. How many numbers can you make out of the digits 1, 2, 3, 4, 6 if the rule is that every digit has to be larger than the digit preceding it? For example 124 is ok, 122 is not ok. Every digit can be used only once, but you do not have to use every digit. A tree might help.arrow_forward
- The director of admissions at Kinzua University in Nova Scotia estimated the distribution of student admissions for the fall semester on the basis of past experience. Admissions Probability 1,100 0.5 1,400 0.4 1,300 0.1 Click here for the Excel Data File Required: What is the expected number of admissions for the fall semester? Compute the variance and the standard deviation of the number of admissions. Note: Round your standard deviation to 2 decimal places.arrow_forwardDo number 3 plsarrow_forward10 plsarrow_forward
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