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3 years ago

How do I do this question, I'm very confused, I need an answer quickly

Mathematics

1 answer:

Sati [7]3 years ago

4 0

1) AB/AC = 1/2
(3x-4)/(2x+12) =1/2
2(3x-4) = 1(2x+12)
6x - 8 = 2x +12
4x = 20 And x = 5

2) Prove AC/BC 2/3 ===== (2x+12)/(7x-2) = 2/3;
Plug in x = 5:

(10+12)/(35-2) = 22/33. Simplify numerator & denominator by 11

(2)(11)/(3)(11) = 2/3

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Please help!

Marat540 [252]

Answer: width = 82.50 m

Step-by-step explanation:

P = 2l x 2w

425 = 2(130) + 2w

425 - 260 = 2w

w = 165 / 2 = 82.50

5 0

3 years ago

Two catalysts may be used in a batch chemical process. Twelve batches were prepared using catalyst 1, resulting in an average yi

aalyn [17]

Answer:

a) $t=\frac{(91-85)-(0)}{2.490\sqrt{\frac{1}{12}}+\frac{1}{15}}=6.222$

$df=12+15-2=25$

$p_v =P(t_{25}>6.222) =8.26x10^{-7}$

So with the p value obtained and using the significance level given $\alpha=0.01$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis.

b) $(91-85) -2.79 *2.490 \sqrt{\frac{1}{12} +\frac{1}{15}} =3.309$

$(91-85) +2.79 *2.490 \sqrt{\frac{1}{12} +\frac{1}{15}} =8.691$

Step-by-step explanation:

Notation and hypothesis

When we have two independent samples from two normal distributions with equal variances we are assuming that

$\sigma^2_1 =\sigma^2_2 =\sigma^2$

And the statistic is given by this formula:

$t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{S_p\sqrt{\frac{1}{n_1}}+\frac{1}{n_2}}$

Where t follows a t distribution with $n_1+n_2 -2$ degrees of freedom and the pooled variance $S^2_p$ is given by this formula:

$\S^2_p =\frac{(n_1-1)S^2_1 +(n_2 -1)S^2_2}{n_1 +n_2 -2}$

This last one is an unbiased estimator of the common variance $\sigma^2$

Part a

The system of hypothesis on this case are:

Null hypothesis: $\mu_2 \leq \mu_1$

Alternative hypothesis: $\mu_2 > \mu_1$

Or equivalently:

Null hypothesis: $\mu_2 - \mu_1 \leq 0$

Alternative hypothesis: $\mu_2 -\mu_1 > 0$

Our notation on this case :

$n_1 =12$ represent the sample size for group 1

$n_2 =15$ represent the sample size for group 2

$\bar X_1 =85$ represent the sample mean for the group 1

$\bar X_2 =91$ represent the sample mean for the group 2

$s_1=3$ represent the sample standard deviation for group 1

$s_2=2$ represent the sample standard deviation for group 2

First we can begin finding the pooled variance:

$\S^2_p =\frac{(12-1)(3)^2 +(15 -1)(2)^2}{12 +15 -2}=6.2$

And the deviation would be just the square root of the variance:

$S_p=2.490$

Calculate the statistic

And now we can calculate the statistic:

$t=\frac{(91-85)-(0)}{2.490\sqrt{\frac{1}{12}}+\frac{1}{15}}=6.222$

Now we can calculate the degrees of freedom given by:

$df=12+15-2=25$

Calculate the p value

And now we can calculate the p value using the altenative hypothesis:

$p_v =P(t_{25}>6.222) =8.26x10^{-7}$

Conclusion

So with the p value obtained and using the significance level given $\alpha=0.01$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis.

Part b

For this case the confidence interval is given by:

$(\bar X_1 -\bar X_2) \pm t_{\alpha/2} S_p \sqrt{\frac{1}{n_1} +\frac{1}{n_2}}$

For the 99% of confidence we have $\alpha=1-0.99 = 0.01$ and $\alpha/2 =0.005$ and the critical value with 25 degrees of freedom on the t distribution is $t_{\alpha/2}= 2.79$

And replacing we got:

$(91-85) -2.79 *2.490 \sqrt{\frac{1}{12} +\frac{1}{15}} =3.309$

$(91-85) +2.79 *2.490 \sqrt{\frac{1}{12} +\frac{1}{15}} =8.691$

7 0

3 years ago

The graph shows which equation?

liraira [26]

Answer:

First option / a - y = 2x - 2

Step-by-step explanation:

We can tell it'll either be the first one or the second one as the line intercepts the y-axis at -2, so the b will be -2.

The line goes up 2 and over 1, so the slope will be 2. Putting all the pieces together gives us the first option of y = 2x - 2.

4 0

3 years ago

THIS IS MY LAST QUESTION PLEASE HELP ME ILL LOVE U FORVER.

hammer [34]

Answer:

Part A: 6250

Part B: No

Step-by-step explanation:

Part B: When Time is 2 Hours, the cost is $30.

30x3=90 < 100

So the unlimited weekly pass is not cheaper

(Find the value of y by given x)

8 0

2 years ago

The perimeter of a square can represent by 16x + 24. Willa wants to write an equivalent expression for the perimeter that shows

Maslowich

The diagram shows that all the sides of the rectangle are congruent. Since the perimeter all of the sides added up, all you have to do is divide the perimeter by 4.

Therefore, the perimeter, which is 16x + 24, can be divided by 4 to find the length of one side.

16x + 24/4 = length of one side. So, the length of one side is 4x + 6.

Hope this helped!

6 0

3 years ago