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grandymaker [24]

2 years ago

12

The circle graph below shows the results of a survey about the number of TV's in a household. If you surveyed 250 households, ho

w many would you predict to have 3 TV's?

1 answer:

Serggg [28]2 years ago

6 0

Answer: answer

Step-by-step explanation: joe nuts

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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

3 years ago

Element A combines with Element B at a ratio of 2:1 to make a particular substance. If you have 10 grams of element A in the sub

Marina86 [1]

If its a 2:1 ratio then 5.

5 0

3 years ago

The. sum of two consecutive. integers. is 17

coldgirl [10]

X+(x+1)=17
So 2x+1=17
Which means 2x=16
Which then means x=8
But you still need the second number, which is x+1, so 8+1=9.
This means that the consecutive numbers are 8 and 9.

6 0

4 years ago

Write one number as a fraction of another and please explain.

nadezda [96]

48 develop a fault out of the total built which is 2400 therefore
48/2400
If needs to be simplified then 1/50

8 0

2 years ago

Lexi needs 144 beads.A large box holds 100 beads.A medium box holds 10 beads.a small box holds 1 bead.lexi already had 1 large b

saveliy_v [14]

The total number of beads that Lexi could accommodate based on the on hand items is 101 beads. Subtract the number of beads she needs which is 144 beads with 101 beads. The amount of beads that would need a box is 43 beads. Since a medium box could only accommodate 10 beads at a time, divide 43 with 10 and the answer would be 4 remainder 3. Thus Lexi would only need 4 medium boxes.

3 0

3 years ago