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2 years ago

NEED HELP ASAP!!!!!!!!

Mathematics

1 answer:

Zolol [24]2 years ago

5 0

Answer:

x = 2.4

y = 31

Step-by-step explanation:

Angle B = 25x

BC = 31

therefore , this is an equilateral triangle all sides and angles are equal,

25x =60

x = 2.4

BC = BA = AC

y= 31

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2. The National Safety Council routinely analyzes the benefit of seat belt use on driver safety. Their data showed that among 28

JulijaS [17]

Answer:

We conclude that there is difference in the proportion of deaths between the 2 groups.

Step-by-step explanation:

We are given that among 2823 drivers not wearing seat belts, 31 died as a result of injuries, and among 7765 drivers wearing seat belts 16 were killed.

Let $p_1$ = proportion of deaths when drivers were not wearing seat belts.

$p_2$ = proportion of deaths when drivers were wearing seat belts.

So, Null Hypothesis, $H_0$ : $p_1=p_2$ {means that there is no difference in the proportion of deaths between the 2 groups}

Alternate Hypothesis, $H_A$ : $p_1\neq p_2$ {means that there is difference in the proportion of deaths between the 2 groups}

The test statistics that would be used here Two-sample z test for proportions;

T.S. = $\frac{(\hat p_1-\hat p_2)-(p_1-p_2)}{\sqrt{\frac{\hat p_1(1-\hat p_1)}{n_1}+\frac{\hat p_2(1-\hat p_2)}{n_2} } }$ ~ N(0,1)

where, $\hat p_1$ = sample proportion of deaths when drivers were not wearing seat belts = $\frac{31}{2823}$ = 0.011

$\hat p_2$ = sample proportion of deaths when drivers were wearing seat belts = $\frac{16}{7765}$ = 0.002

$n_1$ = sample of drivers not wearing seat belts = 2823

$n_2$ = sample of drivers wearing seat belts = 7765

So, the test statistics = $\frac{(0.011-0.002)-(0)}{\sqrt{\frac{0.011(1-0.011)}{2823}+\frac{0.002(1-0.002)}{7765} } }$

= 4.438

The value of z test statistics is 4.438.

Now, at 5% significance level the z table gives critical values of -1.96 and 1.96 for two-tailed test.

Since our test statistic doesn't lie within the range of critical values of z, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.

Therefore, we conclude that there is difference in the proportion of deaths between the 2 groups.

Also, Margin of error (E) = $1.96 \times \sqrt{\frac{\hat p_1(1-\hat p_1)}{n_1}+\frac{\hat p_2(1-\hat p_2)}{n_2} }$

= $1.96 \times \sqrt{\frac{0.011(1-0.011)}{2823}+\frac{0.002(1-0.002)}{7765} }$

= 0.00397

5 0

3 years ago

What is f–1(8)?? Please select the best answer

notka56 [123]

Answer:

$f^{-1}(8)=\frac{3}{2}$

Step-by-step explanation:

Given f(x)= $2x+5$

We have to find $f^{-1}(8)$

In order to find $f^{-1}(x)$ we have to make x as the subject of the formula

Let us assume f(x)=y

⇒ $2x+5=y$

Subtracting both sides by 5

$2x+5-5=y-5$

$2x=y-5$

Dividing both sides by 2

$\frac{2x}{2}=\frac{y-5}{2}$

⇒ $x=\frac{y-5}{2}$

Now substituting y with x

we have $f^{-1}(x)=\frac{x-5}{2}$

Now $f^{-1}(8)=\frac{8-5}{2}$

= $\frac{3}{2}$

So option (ii) is correct

5 0

3 years ago

Read 2 more answers

Solve the equation `x^{4}+13x^{2}+36=0` for all values of `x`.

Zolol [24]

Answer: x4+13x2+36=0

Step-by-step explanation:

Let's solve your equation step-by-step.

x4+13x2+36=0

Step 1: Factor left side of equation.

(x2+4)(x2+9)=0

Step 2: Set factors equal to 0.

x2+4=0 or x2+9=0

7 0

3 years ago

Please all answers I'm in a hurry

givi [52]

#2 is 35°C (just plug in 95 to the formula)

#3:
in the left column are:
(8x-(6+y))
(3/4)w+x^2

in the right column are:
y^2-0.5w
w/4+3(x+y)

to solve you just plug in to the formula

6 0

3 years ago

How do you divide 1.8 and 12

Mariana [72]

Answer:

the answer is 0.15 hope this helped u out

5 0

3 years ago