18 1/2 -2^3•(4 1/3 + 6 4/6)

Please help I am on number 1 please explain

jeka57 [31]

A % is out of a hundred, so you don't need the %/100. Then, you wouldn't do cross multiplication, you would just divide 15/27. Remember, it would be 15/27 because it's percent markup, not the percent the price increased by. So, doing that simple calculation on a calculator you get 0.5555. This converted to a percent is just moving the decimal to the right twice, or multiplied by a 100. That would give you 55.55%, and that's your answer. Make sense?

5 0

3 years ago

The graph of the function f(x) = (x + 2)(x + 6) is shown in the picture

tester [92]

Answer: The function is negative for all real values of x.where

x < -2.

Step-by-step explanation:

Because the values -4 and -6 are less than -2 which is the basis of the statement highlighted as the right one.

6 0

2 years ago

Can you guys and gals help me

professor190 [17]

Answer:

1. B 2. B 3. D 4. A 5. A 6. A 7. B 8. C

Step-by-step explanation:

1. 6 and 8 are right next to each other. Making them 'adjacent angles' as 'adjacent' means 'next to'

2. 2 and 3 are vertically opposite angles, and these angles are equal to each other

3. 3 and 6 are alternate angles. These angles form a 'Z' shape

4. Similar to q2, 1 and 4 are vertically opposite angles

5. Yes they are similar because there are two angles which equal

6. The angles of the big triangle will correlate to the small triangle, therefore x is 40

7. Similar triangles will have the same angles. The top angle of the small triangle is 60, as stated in the big triangle, and 70 is given. The sum of interior angles of a triangle is 180. So, add 60 and 70, then minus from 180

8. Again, same concept as q7, the angles are given to you and you just need to correspond each angle to its respective area, then minus the total of the two given angles from 180

Hope this helped you!!

7 0

3 years ago

Consider a chemical company that wishes to determine whether a new catalyst, catalyst XA-100, changes the mean hourly yield of i

kolezko [41]

Answer:

Null hypothesis: $\mu = 750$

Alternative hypothesis: $\mu \neq 750$

$t=\frac{811-750}{\frac{19.647}{\sqrt{5}}}=6.943$

$p_v =2*P(t_{4}>6.943)=0.00226$

If we compare the p value and a significance level assumed $\alpha=0.05$ we see that $p_v$ so we can conclude that we reject the null hypothesis, and the actual true mean is significantly different from 750 pounds per hour.

Step-by-step explanation:

Data given and notation

Data: 801, 814, 784, 836,820

We can calculate the sample mean and sample deviation with the following formulas:

$\bar X =\frac{\sum_{i=1}^n X_i}{n}$

$s=\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

$\bar X=811$ represent the sample mean

$s=19.647$ represent the standard deviation for the sample

$n=5$ sample size

$\mu_o =750$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

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

State the null and alternative hypotheses to be tested

We need to conduct a hypothesis in order to determine if the mean is different from 750 pounds per hour, the system of hypothesis would be:

Null hypothesis: $\mu = 750$

Alternative hypothesis: $\mu \neq 750$

Compute the test statistic

We don't know the population deviation, so for this case is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

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

t-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".

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

$t=\frac{811-750}{\frac{19.647}{\sqrt{5}}}=6.943$

Now we need to find the degrees of freedom for the t distirbution given by:

$df=n-1=5-1=4$

What do you conclude?

Compute the p-value

Since is a two tailed test the p value would be:

$p_v =2*P(t_{4}>6.943)=0.00226$

If we compare the p value and a significance level assumed $\alpha=0.05$ we see that $p_v$ so we can conclude that we reject the null hypothesis, and the actual true mean is significantly different from 750 pounds per hour.

4 0

3 years ago

Can anyone help me i really need it rn<br>

Hunter-Best [27]

<u>Answer:</u>

11. g

12. f

13. e (add all the frequencies)

14. d

15. c (eg. 17.5 -8.5 = 9)

16. b

17. a

Let me know if you have any questions.

Hope this helps!

4 0

1 year ago