Formulas for the ACT® Science Assessment
The ACT® Science Assessment will test your skills to the limit!
Which skills?
Every skill you’ve acquired at school! From reading to math, including understanding graphs, evaluating models, and evaluating conflicting viewpoints. You’ll need everything if you want to ace the ACT® Science Assessment.
For this test, you won’t need to memorize anything, because all the necessary information will be given to you. However, knowing the necessary formulas for solving the questions at this test will become handy, so here is a formula chart with useful formulas you can use to practice solving our FREE sample test at Union Test Prep.
Category  Formula  Symbols  Comment 

ACT \(\circledR\) Science Assessment 
\(Du = Su \cdot \frac{Du}{Su} \cdot Su \cdot CF\)  Du = Desired Unit Su = Starting Unit CF = Conversion Factor 
Multiple steps may be needed. 
ACT \(\circledR\) Science Assessment 
\(a \cdot b \% = a \cdot \frac{b}{100}\)  a = any real number b% = any percent 
Remember to simplify. (if possible) 
ACT \(\circledR\) Science Assessment 
\(\% = \dfrac{ \lvert ba \rvert}{b} \cdot 100 = \dfrac{c}{b} \cdot 100\)  % = % increase or decrease a = new value b = original value c = amount of change 

ACT \(\circledR\) Science Assessment 
\(rg = lv  sv\)  rg = range lv = largest value in the data set sv = smallest value in the data set 

ACT \(\circledR\) Science Assessment 
\(\overline{x} = \dfrac{\Sigma x_i}{n}\)  \(\overline{x}\) = mean \(x_i\) = value of each measurement n = number of measurements 

ACT \(\circledR\) Science Assessment 
\(Md = (\frac{n+1}{2}) ^{\text{th}}\) term  Md = Median n = number of measurements (odd) 

ACT \(\circledR\) Science Assessment 
\(Md = \dfrac{(\frac{n}{2})^{\text{th}} \text{ term } + (\frac{n}{2} + 1)^ {\text{th}} \text{ term}}{2}\)  Md = Median n = number of measurements (even) 

ACT \(\circledR\) Science Assessment 
\(s = \sqrt{\dfrac{ \Sigma (x_i  \overline{x})^2}{n1}}\)  s = standard deviation \(\overline{x}\) = mean \(x_i\) = value of each measurement n = number of measurements 

ACT \(\circledR\) Science Assessment 
\(V= s^2\)  V = Variance s = standard deviation 

ACT \(\circledR\) Science Assessment 
\(CV = RSD = 100 \cdot \dfrac{s}{\overline{x}}\)  CV = Coefficient of variation RSD = Relative standard deviation s = standard deviation \(\overline{x}\) = mean 
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