Difference between revisions of "SOCR EduMaterials Activities More Examples"

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From a large shipment of peaches, 12 are selected for quality control.  Suppose that in this particular shipment only $65 \%$ of the peaches are unbruised.  If among the 12 peaches 9 or more are unbruised the shipment is classified A.  If between 5 and 8 are unbruised the shipment is classified B.  If fewer than 5 are unbruised the shipment is classified C.  Compute the probability that the shipment will be classified A, B, C. \\[.1in]
 
From a large shipment of peaches, 12 are selected for quality control.  Suppose that in this particular shipment only $65 \%$ of the peaches are unbruised.  If among the 12 peaches 9 or more are unbruised the shipment is classified A.  If between 5 and 8 are unbruised the shipment is classified B.  If fewer than 5 are unbruised the shipment is classified C.  Compute the probability that the shipment will be classified A, B, C. \\[.1in]
  
\noindent We can use the formula and compute
+
We can use the formula and compute
 +
 
 
<math>
 
<math>
 
P(A) = P(X \ge 9) = \sum_{x=9}^{12} {12 \choose x} 0.65^x 0.35^{12-x}=\cdots
 
P(A) = P(X \ge 9) = \sum_{x=9}^{12} {12 \choose x} 0.65^x 0.35^{12-x}=\cdots
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P(b) = P(5 \le X \le 8) = \sum_{x=5}^{8} {12 \choose x} 0.65^x 0.35^{12-x}=\cdots
 
P(b) = P(5 \le X \le 8) = \sum_{x=5}^{8} {12 \choose x} 0.65^x 0.35^{12-x}=\cdots
 
</math>
 
</math>
 +
 
<math>
 
<math>
 
P(A) = P(X < 5) = \sum_{x=0}^{4} {12 \choose x} 0.65^x 0.35^{12-x}=\cdots
 
P(A) = P(X < 5) = \sum_{x=0}^{4} {12 \choose x} 0.65^x 0.35^{12-x}=\cdots
 
</math>
 
</math>
 +
 
Or, much easier use SOCR...  Here is the distribution of the number of unbruised peaches among the 12 selected:
 
Or, much easier use SOCR...  Here is the distribution of the number of unbruised peaches among the 12 selected:
 
\noindent Now that we know how to use the formula, let's use the SOCR applet to answer these questions.  After we enter $n=12$ and $p=0.65$ we get the distribution below:
 
\noindent Now that we know how to use the formula, let's use the SOCR applet to answer these questions.  After we enter $n=12$ and $p=0.65$ we get the distribution below:

Revision as of 02:07, 1 June 2007

Example 1:

From a large shipment of peaches, 12 are selected for quality control. Suppose that in this particular shipment only $65 \%$ of the peaches are unbruised. If among the 12 peaches 9 or more are unbruised the shipment is classified A. If between 5 and 8 are unbruised the shipment is classified B. If fewer than 5 are unbruised the shipment is classified C. Compute the probability that the shipment will be classified A, B, C. \\[.1in]

We can use the formula and compute

\( P(A) = P(X \ge 9) = \sum_{x=9}^{12} {12 \choose x} 0.65^x 0.35^{12-x}=\cdots \)

\( P(b) = P(5 \le X \le 8) = \sum_{x=5}^{8} {12 \choose x} 0.65^x 0.35^{12-x}=\cdots \)

\( P(A) = P(X < 5) = \sum_{x=0}^{4} {12 \choose x} 0.65^x 0.35^{12-x}=\cdots \)

Or, much easier use SOCR... Here is the distribution of the number of unbruised peaches among the 12 selected: \noindent Now that we know how to use the formula, let's use the SOCR applet to answer these questions. After we enter $n=12$ and $p=0.65$ we get the distribution below:

\begin{figure}[h] \includegraphics[height=2.6in, width=5.5in]{peaches1.jpg} \end{figure}

\noindent In the {\it Left Cut Off} and {\it Right Cut Off} boxes (left down corner of the applet) enter the numbers 5 and 8 respectively. What do you observe?

\begin{figure}[h] \includegraphics[height=2.6in, width=5.5in]{peaches2.jpg} \end{figure}

\noindent The distribution is divided into three parts. The left part (less than 5), the right part (above 8), and the between part (between 5 and 8 included). All the SOCR distributions applets are designed in the same way. From the applet the probabilities are $P(A)=0.346653, P(B)=0.627840, P(C)=0.025507$.</math>