If

If BC = 5, DE = 9, and AB = 4, what is the length of AD? 7 8 7.2 7.5

steposvetlana [31]

There are two triangles here: ABC and ADF. These triangles are similar, and thus proportional. So, we can set up a proportion between the left side of each triangle and the base of each triangle.

AB / AD = BC / DE

4 / (4 + BD) = 5 / 9

---AD is made up of AB and DB. We know AB, but not BD, so we need to find its value to find the length of AD.

5(4 + BD) = 9 x 4

20 + 5BD = 36

5BD = 16

BD = 3.2

AD = AB + BD

AD = 4 + 3.2

AD = 7.2

Hope this helps!

8 0

3 years ago

Which equation represents a line that passes through (–2, 4) and has a slope of StartFraction 2 Over 5 EndFraction.? y – 4 = (x

JulijaS [17]

For this case we have that by definition, the point-slope equation of a line is given by:

$(y-y_ {0}) = m (x-x_ {0})$

Where:

$(x_ {0}, y_ {0}):$ It is a point through which the line passes

m: It is the slope of the line

According to the data we have to:

$(x_ {0}, y_ {0}): (-2,4)\\m = \frac {2} {5}$

Substituting:

$y-4 = \frac {2} {5} (x - (- 2))\\y-4 = \frac {2} {5} (x + 2)$

Finally, the equation of the line is:

$y-4 = \frac {2} {5} (x + 2)$

ANswer:

$y-4 = \frac {2} {5} (x + 2)$

8 0

2 years ago

Read 2 more answers

24 cm ,18cm ,c We are looking for c

Ierofanga [76]

Step-by-step explanation:

we can find the value of c by Pythagoras theorem

according to Pythagoras theorem

h² = a² + b²

where

h = hypotenuse (i.e. longest side of a right angled triangle)

a = side

b = base

so, we have to find h or hypotenuse here

h² = (24)² + (18)²

h = 576 + 324 = 900

h² = √900 = 30

c = 30

therefore, value of c is 30.

Hope this answer helps you dear!

3 0

2 years ago

The desired percentage of SiO2 in a certain type of aluminous cement is 5.5. To test whether the true average percentage is 5.5

miskamm [114]

Answer:

z=-3.25

$p_v =2*P(z$

Step-by-step explanation:

1) Data given and notation

$\bar X=5.24$ represent the mean production for the sample

$\sigma=0.32$ represent the sample standard deviation for the sample

$n=16$ sample size

$\mu_o =5.5$ represent the value that we want to test

$\alph=0.05a$ represent the significance level for the hypothesis test.

z would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

Part a: State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean production is different from 5.5 tons, the system of hypothesis would be:

Null hypothesis: $\mu =5.5$

Alternative hypothesis: $\mu \neq 5.5$

If we analyze the info given we know the population deviation so is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{5.24-5.5}{\frac{0.32}{\sqrt{16}}}=-3.25$

P-value

Since this is a two side test the p value would be:

$p_v =2*P(z$

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the production its significant different compared to the desired percentage of SiO2 of 5.5 at 5% of signficance.

7 0

2 years ago

Question 17/23

disa [49]

Answer:

60%

Step-by-step explanation:

Formula:

Percentage decrease = (amount of decrease)/(original price)

✪ Solve ✪

3.85 - 1.54/3.85 x 100

2.31/3.85 x 100 = 60%

Hence, Percent decrease is 60%

~Lenvy

6 0

2 years ago