ch/api/v1/print/highered ... 26. Use common logarithms or natural logarithms and a calculator to evaluate the expression. All Bookmarks log 1811 Paper size Letter Print Use the change of base property to rewrite the given expression. log 18 11 = (Do not evaluate.) Evaluate the expression. log 18 11 ~ (Type an integer or a decimal. Do not round until the final answer. Then round to four decimal places as needed.) 27. Use common logarithms or natural logarithms and a calculator to evaluate the following. log 1 87.5 Use the change of base property to rewrite the given expression. log 14 87.5 = (Do not evaluate.) Evaluate the expression . log 1487.5 ~ (Type an integer or a decimal. Do not round until the final answer. Then round to four decimal places as needed.) 28. The loudness level of a sound can be expressed by comparing the sound's intensity to the intensity of a sound barely audible to the human ear. The formula D = 10 ( log I - log lo ) describes the loudness level of a sound, D, in decibels, where I is the intensity of the sound, in watts per meter, and lo is the intensity of a sound barely audible to the human ear. Use this information to answer parts (a) and (b) below. a. Express the formula so that the expression in parentheses is written as a single logarithm. Choose your answer below. O A. D = 10 log (1-10) O B. OC. D= 10109 To O D. D= 10 log (1.10) b. Use the form of the formula from part ( a) to answer this question. If a sound has an intensity 1,000,000 times the intensity of a softer sound, how much larger on the decibel scale is the loudness level of the more intense sound? decibels louder 29. The formula t = - [ In A - In (A - N)] describes the time, t, in weeks, that it takes to achieve mastery of a portion of a task, where A is the maximum learning possible, N is the portion of the learning that is to be achieved, and c is a constant used to measure an individual's learning style. a. Express the formula so that the expression in brackets is written as a single logarithm. b. Use the form of the formula from part a to answer this question. An animal learning sign language can master a maximum of 91 signs. How many weeks will it take the animal to master 56 signs if the constant c for that animal is 0.04? a. Express the formula in the brackets as a single logarithm. Choose the correct answer below. O A. t= - In [A(A - N)] 1= cln A-N O c. t= - in ( A- N) A O D. t= - In [A - (A -N)] b. It will take the animal weeks to master 56 of 91 signs with c = 0.04 . (Round up to the nearest week.)