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2 years ago

b) 7 of these cuboids of side 3 cm are put together to make this shape. Find the surface area of this shape. (3) Total marks: 5

Mathematics

1 answer:

valentina_108 [34]2 years ago

6 0

Answer: 504 cm^2

The surface area of the shape is:

3 3 * 3=9

9 * 7=63

63+9=72 * 7

=504cm^2

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Solution :

We know that

$H_0: \mu_1 = \mu_2=\mu_3$

$H_1 :$ At least one mean is different form the others (claim)

We need to find the critical values.

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d.f.D = N - k

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$\overline X_1 =50.5$ $\overline X_2 =50.07143$ $\overline X_3 =55.71429$

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The grand mean or the overall mean is(GM) :

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The variance between the groups

$s_B^2=\frac{\sum n_i\left( \overline X_i - \overline X_{GM}\right)^2}{k-1}$

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$=\frac{127.1143}{2}$

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The Variance within the groups

$s_W^2=\frac{\sum(n_i-1)s_i^2}{\sum(n_i-1)}$

$=\frac{(14-1)19.96154+(14-1)14.68681+(7-1)36.57143}{(14-1)+(14-1)+(7-1)}$

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= 20.93304

The F-test statistics value is :

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= 3.036212

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So there is no sufficient evidence to support the claim that there is a difference among the means.

The ANOVA table is :

Source Sum of squares d.f Mean square F

Between 127.1143 2 63.55714 3.036212

Within 669.8571 32 20.93304

Total 796.9714 34

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