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3 years ago

A group of students were given a spelling test

Mathematics

2 answers:

Llana [10]3 years ago

7 0

Answer:

Go on

Step-by-step explanation:

You need to explain more

xxTIMURxx [149]3 years ago

5 0

Answer:

and?

Step-by-step explanation:

???

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A square piece of fabric has an area of 16x^2+40x+25 square inches. The length of each side of the fabric is cx+d, where c and d

lozanna [386]

$A=(cx+d)^2=c^2x^2+2cdx+d^2\\\\c^2x^2+2xcd+d^2=16x^2+40x+25\\\Downarrow\\c^2=16;\ 2cd=40;\ d^2=25\\\Downarrow\\c=\sqrt{16};\ cd=20;\ d=\sqrt{25}\\\Downarrow\\\boxed{c=4\ and\ d=5}\\\\The\ length\ of\ side:cx+d=\boxed{4x+5}\\\\The\ perimeter\ of\ the\ piece\ of\ fabric:4(4x+5)=\boxed{16x+20}\\\\For\ x=2:\\16\cdot2+20=32+20=\boxed{52}$

4 0

3 years ago

A doctor released the results of clinical trials for a vaccine to prevent a particular disease. In these clinical trials, 200,0

CaHeK987 [17]

Answer:

1) No, there is not enough evidence to support the claim that the vaccine was effective (P-value=0.104) .

The null and alternative hypothesis are:

$H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2< 0$

being the subindex 1 for the experimental group and subindex 2 for the control group.

2) Test statistic z=-1.26

Step-by-step explanation:

This is a hypothesis test for the difference between proportions.

The claim is that the vaccine was effective.

Then, the null and alternative hypothesis are:

$H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2< 0$

The significance level is 0.01.

The sample 1 (experimental group), of size n1=100000 has a proportion of p1=0.0002.

$p_1=X_1/n_1=21/100000=0.0002$

The sample 2 (control group), of size n2=100000 has a proportion of p2=0.0003.

$p_2=X_2/n_2=30/100000=0.0003$

The difference between proportions is (p1-p2)=-0.0001.

$p_d=p_1-p_2=0.0002-0.0003=-0.0001$

The pooled proportion, needed to calculate the standard error, is:

$p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{21+30}{100000+100000}=\dfrac{51}{200000}=0.00026$

The estimated standard error of the difference between means is computed using the formula:

$s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.00026*0.99974}{100000}+\dfrac{0.00026*0.99974}{100000}}\\\\\\s_{p1-p2}=\sqrt{0+0.0000000025}=\sqrt{0.0000000051}=0.000071$

Then, we can calculate the z-statistic as:

$z=\dfrac{p_d-(\pi_1-\pi_2)}{s_{p1-p2}}=\dfrac{-0.00009-0}{0.000071}=\dfrac{-0.00009}{0.000071}=-1.26$

This test is a left-tailed test, so the P-value for this test is calculated as (using a z-table):

$P-value=P(z$

As the P-value (0.104) is bigger than the significance level (0.01), the effect is not significant.

The null hypothesis failed to be rejected.

There is not enough evidence to support the claim that the vaccine was effective.

6 0

3 years ago

Simplify. (x6 y3)(−8xy2)(−6x3)

meriva

When simplifying this, we would have to take this little by little in serious steps and not only this, but to also take notice of the use of pemdas and to make sure that we take each step carefully.

We first would (first) simplify the following:

$(((x^6)*(y^3))*(0-(8x*(y^2))))*(0-(2*3x^3)) \\ \\ then \ we \ would \ do . . . . \\ \\ x^7 \ multiplied \ by \ x^3 \ = x^(^7^ +^ 3^) = \ x^1^0 \\ \\ (last \ step).... \\ \\ 2^3 \ multiplied \ by \ 2^1 = 2^(^3^ +^ 1^) = 2^4 \\ \\ \Longrightarrow \ (your \ answer) \\ \\ \boxed{\bf{ (2^4*3x^1^0y^5)}}$

7 0

3 years ago

I need help quick please

kenny6666 [7]

Volume is Length x width x height divided by 3. You have the length and the width. which equals 24. (6x4). The volume that is present is 72... the last thing you do in the equation is divide by three so multiply 72 by 3 and get 216. This is the LxWxH. Like I said before you have the L and the W, which is 24. You would divide 24 from 216. The Height is 9cm.

6 0

3 years ago

Read 2 more answers

You and your brother are reading the same novel. You want to get ahead of him in the book, so you decide to read 30 minutes long

Sholpan [36]

Answer: its 45 if i read it right.

Step-by-step explanation:

8 0

3 years ago