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1 year ago

10

Three straight lines intersect at $O$, and ray $\overrightarrow{OD}$ divides $\angle COE$ into two angles of equal measure. The

ratio of $\angle COB$ to $\angle BOF$ is $7:2$. What is the number of degrees in $\angle COD$?

1 answer:

riadik2000 [5.3K]1 year ago

8 0

Answer:

12

Step-by-step explanation:

m xxq

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Rachel has completed 2/3 of her shift; Jose has completed 1/6 of his shift; Damon has finished 4/5 of his shift; and Stacy has 6

Alisiya [41]

Answer:

C. Stacy

Step-by-step explanation:

One way to compare is to convert all the fractions into decimals

Rachel works 2/3 of her shift: Approximately= 0.667

Jose works 1/6: approx. = 0.1667

Damon works 4/5= 0.80

Stacy works 6/7: approx. = 0.8571

Now this makes it much easier to compare

And since 0.85714 (Stacy's shift) is the largest number, Stacy has completed the largest portion of her shift

4 0

2 years ago

A point in the figure is selected at random. Find the probability that the point will be in the part that is NOT shaded.

Dovator [93]

Answer:

B

Step-by-step explanation:

So the question really is what is the probability that the point is in the square? You cannot pick something surrounding the circles because you do not know anything about that region.

This is solved by comparing areas. There are 2 full circles there. 1 circle has an area of pi*r^2

Total shaded area = 2 * pi * r^2.

Let r = 3 This is a completely random choice. No matter what number you choose for r, the answer will come out the same. When you get along a little further in math, you will find that you can just use letters.

Total shaded area = 2 * 3.14 * 3^2

Total shaded area = 2 * 3.14 * 9

Total shaded area = 56.55

Total area of the square.

s = 2*r

s = 2*3

s = 6

Area of the square = 6^2 = 36

Total area of both regions = 56.55 + 36 = 92.55

Answer

% = (area of square) * 100% / Total area of both regions

% = 3600 / 92

% = 39%

Obviously the answer I get is not offered. The closest answer is B so I will choose that.

==========================

This is how this question would be done without using any value for r.

Area of shaded region = 2 pi r^2 = 6.28 r^2

Area of square = d^2 where d = 2r

Area of square = 4 r^2

Total area = 6.28 r^2 + 4r^2 = 10.28 r^2

Area of square to total = (4r^2/10.28 r^2 ) * 100%

Area of square to total (as a %) = 4/10.28 * 100 = 39% which gives the same answer.

7 0

2 years ago

Read 2 more answers

The Tennessee Tourism Institute (TTI) plans to sample information center visitors entering the state to learn the fraction of vi

baherus [9]

Answer: 2185

Step-by-step explanation:

Let p be the proportion of visitors are campers.

Given : The Tennessee Tourism Institute (TTI) plans to sample information center visitors entering the state to learn the fraction of visitors who plan to camp in the state.

The prior proportion of visitors are campers : p=0.35

Allowable error : E= 2%= 0.02

We know that the z-value for 95% confidence = $z_c=1.96$

Then by Central Limit Theorem , the required sample size would be :

$n=p(1-p)(\dfrac{z_{c}}{E})^2$

$\Rightarrow\ n=0.35(1-0.35)(\dfrac{1.96}{0.02})^2\\\\ n= 0.35(0.65)(9604)$

Simply , we get

$n=2184.91\approx2185$ [Rounded to the next whole number.]

Hence, the smallest sample size to estimate the population proportion of campers =2185

7 0

1 year ago

Sam spent 5/6 of an hour at the dentist’s office. He spent 1/10 of the time in the waiting room. How much time did he spend at t

svp [43]

That is 5/6 - 5/6 * 1/10 = 5/6 - 5/60 = 50/60 - 5/60 = 45/60 = 3/4 hour answer

4 0

1 year ago

A new curing process developed for a certain type of cement results in a mean compressive strength of 5000 kilograms per square

Sedbober [7]

Answer:

$\alpha =0.0668$

Step-by-step explanation:

Data given and notation

The info given by the problem is:

$n=25$ the random sample taken

$\mu =5000$ represent the population mean

$\sigma =100$ represent the population standard deviation

The critical region on this case is $\bar X$ so then if the value of $\bar X \geq 4970$ we fail to reject the null hypothesis. In other case we reject the null hypothesis

Null and alternative hypotheses to be tested

We need to conduct a hypothesis in order to determine if the true mean is 5000, the system of hypothesis would be:

Null hypothesis: $\mu = 5000$

Alternative hypothesis: $\mu \neq 5000$

Let's define the random variable X ="The compressive strength".

We know from the Central Limit Theorem that the distribution for the sample mean is given by:

$\bar X \sim N(\mu , \frac{\sigma}{\sqrt{n}})$

Find the probability of committing a type I error when H0 is true.

The definition for type of error I is reject the null hypothesis when actually is true, and is defined as $\alpha$ the significance level.

So we can define $\alpha$ like this:

$\alpha= P(Error I)= P(\bar X$

And in order to find this probability we can use the Z score given by this formula:

$Z=\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And the value for the probability of error I is givn by:

$\alpha= P(\bar X$

4 0

1 year ago