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SSSSS [86.1K]
2 years ago
4

The brain volumes ​(cm cubed​)of 50 brains vary from a low of 904cm cubedto a high of 1490cm cubed.Use the range rule of thumb t

o estimate the standard deviation s and compare the result to the exact standard deviation of 174.7cm cubed​,assuming the estimate is accurate if it is within 15 cm cubed.The estimated standard deviation is 146.5cm cubed.​(Type an integer or a decimal. Do not​ round.)Compare the result to the exact standard deviation.
Mathematics
2 answers:
vovangra [49]2 years ago
5 0

Answer:

x_bar = 1197 cm^3 , s.d_e = 146.5 cm^3

Outside the 15 cm^3 tolerance. Not a good estimation.

Step-by-step explanation:

Given:

- Lowest value of brain volume L = 904 cm^3

- Highest value of brain volume H = 1490 cm^3

- Exact standard deviation s.d_a = 174.7 cm^3

Find:

Use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 174.7 cm^3 assuming the estimate is accurate if it is within 15 cm^3.

Solution:

- The rule of thumb states that the max and min limits are +/- 2 standard deviations about the mean x_bar. Hence, we will set up two equations.

                           L = x_bar - 2*s.d_e

                           H = x_bar + 2*s.d_e

Where, s.d_e is the estimated standard deviation.

- Solve the two equations simultaneously and you get the following:

                          x_bar = 1197 cm^3 , s.d_e = 146.5 cm^3

- The exact standard deviation is s.d_a = 174.7 cm^3

So, the estimates differs by:

                           s.d_a - s.d_e = 174.7 - 146.5 = 28.2 cm^3

Hence, its outside the tolerance of 15 cm^3. Not a good approximation.

astraxan [27]2 years ago
4 0

Answer:

The Range Rule of Thumb says that the range is about four times the standard deviation. So, if you need to calculate it, you need to divide range (Maximum - Minimum) with 4, S=\frac{R}{4}.

Step-by-step explanation:

R=1490 - 904

S = 586 / 4 = 149.5

If you compare the exact standard desviation (149.5 cm) with the estimated (146.5 cm), it is a difference of 3 cm, is not neccesary round the result.

Hope my answer has been useful.

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Step-by-step explanation:

The <em>probaility</em> of an event is defined as the number of favorable outcomes divided by the number of total possible events.

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The results of the rolling two dice are summarized in this table:

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  3                                     (3,1)  (3,2)  <u>(3,3)</u>   (3,4)  (3,5)  (3,6)

  4                                     (4,1)   (4,2)  (4,3)  (4,4)  (4,5)  (4,6)

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Step-by-step explanation:

The given question is incomplete; here is the complete question.

The cost of maintaining a school is partly constant and partly varies as the number of pupils. With 50 pupils, the cost is $15,705.00 and with 40 pupils, it is $13,305.00.

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(b) If the fee per pupil is $360.00, what is the least number of pupils for which the school can run without a loss?

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    By subtracting equation (2) from equation (1),

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    360p ≥ 3705 + 240p

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Answer:

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Step-by-step explanation:

Combining the equations is also known as substitution. This is done when you substitute one variable into another equation.

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Let's change the second equation into one with one variable on each side.

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Now, plug this into your first equation.

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Distribute the + sign.

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Your solution is (-10, 6).

Check this by plugging in these values into the equation you have not checked yet.

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