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3 years ago

I WILL GIVE 175 POINTS TO ANYONE WHO HELPS ON ALL QUESTIONS

Mathematics

1 answer:

anzhelika [568]3 years ago

8 0

Answer:

--No answers here, just an additional question---

Question:

What in the heck is this : 푦

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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

2 years ago

Matrix multiplication was used to encode a message using the given encoding matrix: [i 47 A=1 |-1 -3] The original message was c

nadya68 [22]

Answer:

$A^{-1}=\left[\begin{array}{cc}-3&-4\\1&1\end{array}\right]$ message SHOW_ME_THE_MONEY_

Step-by-step explanation:

The matrix

$A=\left[\begin{array}{cc}1&4\\-1&-3\end{array}\right]\rightarrow |A|=(1 \times -3)-(-1\times 4)=1\\\rightarrow A^{-1}=\left[\begin{array}{cc}-3&-4\\1&1\end{array}\right] \\$

We can check that in fact A*A^⁻1=I_2 the identity matrix of size 2 x 2.

Now the message was divided in 1 x 2 matrices, then we have that the sequence given is the result of multiplying m by A, so to get m again we multiply now by A^⁻1. and we get the next table

Encoded message Decoded message message in letters by association

11 52 19 8 S H

-8 -9 15 23 O W

-13 -39 0 13 _ M

5 20 5 0 E _

12 56 20 8 T H

5 20 5 0 E _

-2 7 13 15 M O

9 41 14 5 N E

25 100 25 0 Y _

Then the message decoded is SHOW_ME_THE_MONEY_

3 0

2 years ago

The table below represents the distance of a car from its destination as a function of time.

KIM [24]

We are given the table that projects the distance of the car per hour. x is associated to time while y is associated to distance. The equation of the line after plotting in MS Excel is y = 900 - 50x. Hence the y-intercept is equal to 900 while the slope is equal to -50. The domain of the function that is x is all positive numbers.

7 0

3 years ago

Madeline spent 4 hours at the gym each week how much time does he spend at the gym in an 8 week period.

emmasim [6.3K]

He spends 32 hours in the gym in an 8 week period. (8*4)

5 0

2 years ago

Whoever gets it right can have brainliest, but answer ASAP!

sdas [7]

Answer:

6.52

Step-by-step explanation:

6.52

6 0

2 years ago

Read 2 more answers