intermediate algebra and pre statistic test in morning 8amMath 30+ Review #4 Solutions for...

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intermediate algebra and pre statistic test in morning 8amMath 30+ Review #4   Solutions for selected exercises      Instructions for the exam  Show all work for full credit. Clearly circle or box your answers when applicable. When  rounding final answers, use three decimal places (unless there are fewer than 3, or unless 3  decimals is inappropriate for the context of the problem). You may use a pencil, eraser, ruler  (or other straight edge), scientific calculator, StatCrunch, the e-text, and desmos.com.    PS 8.1, 8.2, and 8.3    3)  Solve  ??−? ? = ??+? ?   Lcd is 6: ? ( ??−? ? ) = ? ( ??+? ? )  ?(?? − ?) = ?(?? + ?)  ?? − ? = ?? + ?  ?? − ?? = ? + ?  ? = ?  Check:  ?(?)−? ? = ?(?)+? ?  ?  …     5)  The sales of musical instruments were $?. ?? million in 2010, and they decreased by  about $?. ?? million per year until 2014.     a)  Find an equation of a linear model that describes the situation. Explain what the  variables represent. (Hint: one of the variables will have to represent the number of  years since 2010).    Let ? = number of years since 2010, and let ?(?) = sales ? years after 2010, then   ?(?) = ?? + ?  ? = 0  year 2010, when sales = $6.39 million  y-intercept = (0, 6.39)  b = 6.39  Decrease of $0.28 million  r.o.c. = m = -0.28  Equation: ?(?) = −?. ??? + ?. ??, in millions of dollars    b)  Predict the amount of sales in 2017.    2017  ? = ?  ?(?) = −?. ??(?) + ?. ?? = ?. ??  sales were $4.43 million in 2017    c)  Estimate in which year sales were $?. ? million.    ?. ? =  −?. ??? + ?. ??  −?. ?? = −?. ???  ?. ?? … = ?  So ? ≈ ?. ?   ? ≈ ?. ? years since 2010 puts it right at the end of 2013, but this still means it hits the  sales of $5.3 million in the year 2013.   IA 1.3    6)  Suppose that the percentages of men and women, ?(?) and ?(?) respectively, who have  completed for or more years of college are modeled by the system     ? = ?(?) = ?. ??? + ??. ??        ? = ?(?) = ?. ??? + ??. ??     where ? is the number of years since 1990.    a)  Use substitution or elimination to estimate when the percentage of women who  have completed four or more years of college was equal to the percentage of men  who had completed four or more years of college.    Ie: find ? such that the expressions ? = ?(?) and ? = ?(?) are equal. To do this,  substitute the expression for ?(?) in for ? in the equation ? = ?(?):  ?(?) = ?(?)  Then  substitute in the respective equations:  ?. ??? + ??. ?? =  ?. ??? + ??. ??  And solve for ?:  ?. ??? − ?. ??? = ??. ?? − ??. ??  ?. ??? = ?. ??  ? = ??. ?? … ≈ ??. ?    About 22.9 years after 1990 is towards the end of 2012. So the percentage of women who  completed least 4 years of college equaled the percentage of men who completed at least 4  years of college somewhere near the end of 2012.      b)  What was that percentage?  ?(??. ?) = ?(??. ?) =  ?. ??(??. ?) + ??. ?? = ??. ?  So about 31.4% of both men and women had completed at least 4 years of college by the  end of 2012.  PS 8.4 & IA 3.5 (IA 3.5 was absorbed into PS 8.4 lecture)    7) Solve the following formulas for the specified variable.    a) ?(? ?? ?) = ?(?) + ?(?) − ?(? ??? ?); for ?(?)      ?(? ?? ?) − ?(?) + ?(? ??? ?) = ?(?) + ?(?) − ?(?) − ?(? ??? ?) + ?(? ??? ?)  ?(? ?? ?) − ?(?) + ?(? ??? ?) = ?(?) b) ?? =  ?? √?−? ; for ?  ?? =  ?? √?−?       (√? − ?) ∙ ?? = (√? − ?) ∙ ?? √?−?       (√? − ?) ∙ ?? = ??      √? − ? = ?? ??     (√? − ?) ? = ( ?? ?? ) ?      ? − ? = ( ?? ?? ) ?       ? = ( ?? ?? ) ? + ?          PS 8.5   9)  Solve the compound inequality  ? ≤ ?(? − ?) ≤ ?. Describe the solution set as an  inequality, in interval notation, and on a graph. ? ≤ ?(? − ?) ≤ ?  ? ≤ ? − ?? ≤ ?  −? ≤ −?? ≤ −?  −? −? ≥ ? ≥ −? −?   Inequality:  ? ? ≥ ? ≥ ? ?  or, equaivalently,  ? ? ≤ ? ≤ ? ?   Interval: [ ? ? , ? ? ]  Graph: IA 4.1    10) Solve ? − |??? + ? ? | = −?  ? − |??? + ? ? | = −?  − |??? + ? ? | = −?  |??? + ? ? | = ?  …so ??? + ? ? , whatever it is, is a distance of 6 away from 0 on the number line. Only two  numbers are 6 away from 0 on the number line, namely -6 and 6. So…  ??? + ? ? = −?  ??? + ? = −??  ??? = −??  ? = − ?? ??  Or        Or   ??? + ? ? = ?    ??? + ? = ??  ??? = ?  ? = ? ?? = ? ?   Check by plugging both solutions back in to the original equation or by graphing.   13) Solve |?? + ?| − ?

Rajeswari · Accepted Answer

61461 assignment
Check: substitute q =8 and we find left side=right side = 11
(Note: Here y intercept in real life is at the beginning of counting of the years, the initial consumption was 39.19 lbs)
The interval is [-7, -14/3] closed both sides.
The graph is the red shaded part between -7 and -14/3 including both end points.

Math 30+ Review #4 Solutions for selected exercises Instructions for the exam Show all work for full credit. Clearly circle or box your answers when applicable. When rounding final answers, use three...

Answer To: Math 30+ Review #4 Solutions for selected exercises Instructions for the exam Show all work for full...

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