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3 years ago

Work out and explain angle size - i will mark you as brainliest

Mathematics

1 answer:

postnew [5]3 years ago

6 0

∠AXY=∠XBC=55°(corresponding angles)

XB=XC⇒ΔXBC is isosceles, so ∠XBC=∠XCB=55°

The sum of all the angles in a triangle is 180°⇒

55°+55°+∠BXC=180°

∠BXC=70°

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PLZZZZZZ help with this

vlabodo [156]

Answer:

28m⁷n⁵

Step-by-step explanation:

You would first multiply 14 by 2. You would then multiply (which is really addition when it comes to exponents) your like-term exponents.

(14m²n⁵)(2m⁵) =28m⁷n⁵

14(2) = 28

m² + m⁵=m⁷

n⁵ + 0 = n⁵

4 0

3 years ago

Read 2 more answers

A random sample of size n1= 25, taken from a normal population with a standard deviation σ1= 5, has a mean X1= 80. A second rand

sesenic [268]

Answer:

The 94% confidence interval would be given by $2.898 \leq \mu_1 -\mu_2 \leq 7.102$

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X_1 =80$ represent the sample mean 1

$\bar X_2 =75$ represent the sample mean 2

n1=25 represent the sample 1 size

n2=36 represent the sample 2 size

$\sigma_1 =5$ sample standard deviation for sample 1

$\sigma_2 =3$ sample standard deviation for sample 2

$\mu_1 -\mu_2$ parameter of interest.

The confidence interval for the difference of means is given by the following formula:

$(\bar X_1 -\bar X_2) \pm z_{\alpha/2}\sqrt{\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2}}$ (1)

The point of estimate for $\mu_1 -\mu_2$ is just given by:

$\bar X_1 -\bar X_2 =80-75=5$

Since the Confidence is 0.94 or 94%, the value of $\alpha=0.06$ and $\alpha/2 =0.03$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.03,0,1)".And we see that $z_{\alpha/2}=1.88$

The standard error is given by the following formula:

$SE=\sqrt{\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2}}$

And replacing we have:

$SE=\sqrt{\frac{5^2}{25}+\frac{3^2}{36}}=1.118$

Confidence interval

Now we have everything in order to replace into formula (1):

$5-1.88\sqrt{\frac{5^2}{25}+\frac{3^2}{36}}=2.898$

$5+1.8\sqrt{\frac{6^2}{36}+\frac{7^}{49}}=7.102$

So on this case the 94% confidence interval would be given by $2.898 \leq \mu_1 -\mu_2 \leq 7.102$

7 0

3 years ago

144 = -12 (x + 5) find x Show work.

kumpel [21]

Answer:

-17 =x

Step-by-step explanation:

144 = -12 (x + 5)

Divide each side by -12

144/-12 = -12 (x + 5)/-12

-12 = x+5

Subtract 5 from each side

-12-5 =x+5-5

-17 =x

3 0

3 years ago

Read 2 more answers

Find the value of :

beks73 [17]

Answer:

i) 66

ii) 536

Step-by-step explanation:

Check attachement(s) for solution.

Attachment - 1: Solution (i)
Attachment - 2: Solution (ii)

7 0

2 years ago

If x<0 and y>0, determine the sign of the real number x-y/xy ...?

Ludmilka [50]

If x<0 and y>0, then the sign of the real number x-y/xy would be positive. If x is negative and y is positive then x-y is negative and xy is negative. A negative number divided by another negative number would be positive. Hope this answers the question.

4 0

3 years ago