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3 years ago

Simplify: 1/2n – 1/4n + 1/3a + 1/2a

Mathematics

1 answer:

vova2212 [387]3 years ago

7 0

Answer:

Step-by-step explanation:

make common denominators

2/4n - 1/4n + 2/6a + 3/6a

add common equations

1/4n + 5/6a

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In a completely randomized experimental design, three brands of paper towels were tested for their ability to absorb water. Equa

arlik [135]

Answer:

Yes. At this significance level, there is evidence to support the claim that there is a difference in the ability of the brands to absorb water.

Step-by-step explanation:

<em>The question is incomplete:</em>

<em>The significance level is 0.05.</em>

<em>Brand X: 91, 100, 88, 89</em>

<em>Brand Y: 99, 96, 94, 99</em>

<em>Brand Z: 83, 88, 89, 76</em>

We have to check if there is a significant difference between the absorbency rating of each brand.

Null hypothesis: all means are equal

$H_0:\mu_x=\mu_y=\mu_z$

Alternative hypothesis: the means are not equal

$H_a: \mu_x\neq\mu_y\neq\mu_z$

We have to apply a one-way ANOVA

We start by calculating the standard deviation for each brand:

$s_x^2=30,\,\,s_y^2=6,\,\,s_z^2=35.33$

Then, we calculate the mean standard error (MSE):

$MSE=(\sum s_i^2)/a=(30+6+35.33)/3=71.33/3=23.78$

Now, we calculate the mean square between (MSB), but we previously have to know the sample means and the mean of the sample means:

$M_x=92,\,\,M_y=97,\,\,M_z=84\\\\M=(92+97+84)/3=91$

The MSB is then:

$s^2=\dfrac{\sum(M_i-M)^2}{N-1}\\\\\\s^2=\dfrac{(92-91)^2+(97-91)^2+(84-91)^2}{3-1}\\\\\\s^2=\dfrac{1+36+49}{2}=\dfrac{86}{2}=43\\\\\\\\MSB=ns^2=4*43=172$

Now we calculate the F statistic as:

$F=MSB/MSE=172/23.78=7.23$

The degrees of freedom of the numerator are:

$dfn=a-1=3-1=2$

The degrees of freedom of the denominator are:

$dfd=N-a=3*4-3=12-3=9$

The P-value of F=7.23, dfn=2 and dfd=9 is:

$P-value=P(F>7.23)=0.01342$

As the P-value (0.013) is smaller than the significance level (0.05), the null hypothesis is rejected.

There is evidence to support the claim that there is a difference in the ability of the brands to absorb water.

3 0

3 years ago

Every economic decision has only positive benefits. gained opportunities. unavoidable limitations. a consequence or tradeoff.

Alina [70]

Every economic decision has "a consequence or tradeoff" - this final answer choice is correct. Every time that an individual, business, or institution makes an economic decision, they always forgo an opportunity to use the same capital or resources for other endeavors. As such, there is a tradeoff incurred by not making the decision to use the resource in another manner. This is known as opportunity cost and is one of the fundamental tenets of economic theory.

3 0

4 years ago

Read 2 more answers

If it’s costs 60 cents for 125 grammes. How much would 100 grammes cost?

beks73 [17]

<h3>✽ - - - - - - - - - - - - - - - ~Hello There!~ - - - - - - - - - - - - - - - ✽</h3>

➷ Work out the cost per gram

60/125 = 0.48

It costs 0.48 cents per gram

Multiply this by 100 to get the answer:

0.48 x 100 = 48

It would cost 48 cents