(i)[2]
Determine the value of $k$.
(ii)[2]
Determine the standard deviation of $x$.
Mathematics 9709 · AS & A Level · Continuous random variables
Continuous random variables — practice question
Kadijat recorded the masses, $x$ grams, of 30 chocolate buns. Her findings are given by $\sum (x-k) = 315$, $\sum (x-k)^2 = 4022$, where $k$ is a constant. The buns have a mean mass of $50.5$ grams.
Worked solution & mark scheme
This 4-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Apply the coded mean formula, for example $\sum \frac{x}{30}-k=\frac{315}{30}=10.5$, or an equivalent working” …
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