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2 years ago

20 POINTS HELP FAST

Mathematics

2 answers:

olga nikolaevna [1]2 years ago

3 0

Answer:

the answer is 20/72 = x/480 . this is because u have to add the numbers for the first sample to find the sample size and then make a ratio to determine if the sample size increases to 480 .

Alenkinab [10]2 years ago

3 0

Answer:

its D.

Step-by-step explanation:

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What is the inverse of the function f(x) = 3x – 2?<br> f-1(x) =

Eddi Din [679]

Answer:

$\frac{x + 2}{3}$

Step-by-step explanation:

Replace y with f(x).

$y = 3x - 2$

Swap x and y and solve for y

$x = 3y - 2$

$x + 2 = 3y$

$\frac{x + 2}{3} = y$

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3 years ago

Will mark brainless

iren2701 [21]

Answer:

Step-by-step explanation:

y = 3x + 2

6x – 2y = 10

Ryan’s answer:

I solved by adding the equations. The solution is .

y = 3x + 2 → 3x + y = 2

6x – 2y = 10 → 3x – y = 5

6x = 7

x =

6x – 2y = 10 → 6 – 2y = 10

7 – 2y = 10

–2y = –3

y = -

Jesse’s answer:

I used matrices. The solution is .

Mark’s answer:

I graphed the equations. The lines are parallel and do not intersect, so there is no solution.

6 0

3 years ago

0=4t-16t^2 Solve this please

vaieri [72.5K]

Answer:

$\large\boxed{t=0\ \vee\ t=\dfrac{1}{4}}$

Step-by-step explanation:

$4t-16t^2=0\qquad\text{divide both sides by 4}\\\\\dfrac{4t}{4}-\dfrac{16t^2}{4}=\dfrac{0}{4}\\\\t-4t^2=0\\\\t(1-4t)=0\iff t=0\ \vee\ 1-4t=0\\\\1-4t=0\qquad\text{subtract 1 from both sides}\\\\-4t=-1\qquad\text{divide both sides by (-4)}\\\\t=\dfrac{1}{4}$

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3 years ago

Where does the graph of the line y = x − 2 intersect the x-axis

arsen [322]

(0,2) is your answer

Explanation

5 0

2 years ago

News article reports that "Americans have differing views on two potentially inconvenient and invasive practices that airports c

OverLord2011 [107]

Answer:

1) p1=0.83

2) p2=0.81

3) Option B

4) p=0.82

5) s=0.03

6) z=0.67

7) P=0.50

8) Do not reject H0

Step-by-step explanation:

1) The proportion of Republicans who think the full-body scans should be applied in airports is equal to the ratio between the republicans that think it should over the total Republicans in the poll:

$p=X/n=258/311=0.83$

2) The proportion of Democrats who think the full-body scans should be applied in airports is equal to:

$p=X/n=294/363=0.81$

3) As we want to know if there is a difference in the proportions calculated, not if one is higher or lower than the other, the correct option is B:

$H_0:p_1-p_2=0\\\\H_a:p_1-p_2\neq0$

4) The pooled estimate of a proportion is the average of both proportions:

$\bar{p}=\frac{p_1+p_2}{2}= \frac{0.83+0.81}{2}=0.82$

5) The standard error can be calculated as:

$s=\sqrt{\frac{\bar{p}(1-\bar{p})}{n_1} +\frac{\bar{p}(1-\bar{p})}{n_2}} \\\\s=\sqrt{\frac{0.82*0.18}{311} +\frac{0.82*0.18}{363}} \\\\s=\sqrt{0.00047+0.00041} =\sqrt{0.00088}=0.03$

6) The z-statistic can be calculated as:

$z=\frac{p_1-p_2}{s}=\frac{0.83-0.81}{0.03}=\frac{0.02}{0.03}=0.67$

7) The P-value for z=0.67 is P=0.50 (from the standard normal distribution table).

$2P(Z>|z|)=0.50286$

8) If the significance level is 0.01, the P-value is bigger than the significance level. The effect is not significanct. The null hypothesis is not rejected.

There is not enough evidence to say that both proportions are different.

A. Do not reject H0

8 0

2 years ago