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Math Help - Failure rate of a electrical device

  1. #1
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    Failure rate of a electrical device

    Question : The failure rate of a certain electronic device is suspended to increase linearly with its temparature. Fit a least squares linear line through the data (two measurements were taken for each given temparature)
    <br />
\begin{array}{c|c|c|c|c|c|c}<br />
Temp \ F & 55  & 65 & 70 & 85 & 95 & 105 \\<br />
\hline<br />
Failure \ rate \   10^6 & 1.90 & 1.93 & 1.97 & 2.00 & 2.01 & 2.01 \\<br />
.  & 1.94 & 1.95 & 1.97 & 2.02 & 2.02 & 2.04 \\<br />
\end{array}

    i) Obtain desired least square line
    ii) Obtain predicted failure rate at 70^{\cdot} F
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  2. #2
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    Quote Originally Posted by zorro View Post
    Question : The failure rate of a certain electronic device is suspended to increase linearly with its temparature. Fit a least squares linear line through the data (two measurements were taken for each given temparature)
    <br />
\begin{array}{c|c|c|c|c|c|c}<br />
Temp \ F & 55 & 65 & 70 & 85 & 95 & 105 \\<br />
\hline<br />
Failure \ rate \ 10^6 & 1.90 & 1.93 & 1.97 & 2.00 & 2.01 & 2.01 \\<br />
. & 1.94 & 1.95 & 1.97 & 2.02 & 2.02 & 2.04 \\<br />
\end{array}

    i) Obtain desired least square line
    ii) Obtain predicted failure rate at 70^{\cdot} F
    See: least squares

    CB
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  3. #3
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    Issues

    Quote Originally Posted by CaptainBlack View Post

    In the table there are 2 reading provided for frequency so how should i incorporate it in the formula.............please advice
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  4. #4
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    I would take the average of the two values.
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    Is this correct?

    Quote Originally Posted by ANDS! View Post
    I would take the average of the two values.

    that means the for example for the first reading the value is as below:

    \frac{1.90 + 1.94}{2} = 1.92
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    Quote Originally Posted by zorro View Post
    In the table there are 2 reading provided for frequency so how should i incorporate it in the formula.............please advice
    You have 12 data points, the equations do not care that some are for the same independent variable value.

    CB
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  7. #7
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    Quote Originally Posted by zorro View Post
    that means the for example for the first reading the value is as below:

    \frac{1.90 + 1.94}{2} = 1.92
    That will work but is unnecessary, see previous post.

    CB
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  8. #8
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    Quote Originally Posted by ANDS! View Post
    I would take the average of the two values.
    Why would you want to do that? The regression equations work without any assumptions about non-repeating independent variable values. In this case there are 12 data points some of which have the same y values.

    CB
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  9. #9
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    Thank you CaptainBlack

    Quote Originally Posted by CaptainBlack View Post
    Why would you want to do that? The regression equations work without any assumptions about non-repeating independent variable values. In this case there are 12 data points some of which have the same y values.

    CB

    Thankyou CaptainBlack for helping me
    cheer mite




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