1 question, Thanks if you answer, will mark brainliest.

47 of the birthday cake was eaten on your birthday. The next day your dad ate 23 of what was left. You are given what your dad l

Lyrx [107]

I think the best approach is assuming in percentage. if the cake= 100, then just add the 47 and 23. that would equal 70. then, subtract the 70 from the 100. that would be 30 as your final answer.
« 47+23+?=100 »
« 70+?=100 »
-70 -70
?=30

5 0

2 years ago

Need help answering these five geometry questions I need answers

andriy [413]

Answer:

If you help me I will help you

Step-by-step explanation:

3 0

4 years ago

A student is taking a 3 question multiple choice test. Each question has 4 options. If all the students completely guessed on ev

Oksanka [162]

Answer: Second graph.

Step-by-step explanation:

We have 3 questions, and each question has 4 options.

Then, the probability to having one question correct by selecting an option at random is 1/3 = 0.25.

Now, the probability of answering incorrectly the question is 1 - 0.25 = 0.75

Now let's analyze the options:

Having the 3 questions wrong.

Here we have 3 times the probability of 0.75, then the joint probability is:

P = 0.75*0.75*0.75 = 0.42

Whit this we can discard the third graph, now let's calculate the probability of having one answer correct.

The probabilities are two times 0.75 and one times 0.25, but in this case, we have 3 possible combinations ( the correct one is the first, the correct one is the second, the correct one is the third) so we need to also add a factor of 3.

P = 0.75*0.75*0.25*3 = 0.42

Whit only these two calculations we can see that the correct graph is the second graph.

We could also calculate the probabilities of having 2 correct answers (again, here we have 3 permutations, this time for the incorrect answer):

P = 0.25*0.25*0.75*3 = 0.14

The probability of having 3 correct answers is:

P = 0.25*0.25*0.25 = 0.02

4 0

3 years ago

A union of restaurant and foodservice workers would like to estimate the mean hourly wage, μ, of foodservice workers in the U.S.

pav-90 [236]

Answer:

$n=(\frac{1.960(2.25)}{0.35})^2 =158.76 \approx 159$

So the answer for this case would be n=159 rounded up to the nearest integer

Step-by-step explanation:

Assuming this complete question: A union of restaurant and foodservice workers would like to estimate the mean hourly wage, , of foodservice workers in the U.S. The union will choose a random sample of wages and then estimate using the mean of the sample. What is the minimum sample size needed in order for the union to be 95% confident that its estimate is within $0.35 of ? Suppose that the standard deviation of wages of foodservice workers in the U.S. is about $2.15 .

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".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma=2.25$ represent the population standard deviation

n represent the sample size

Solution to the problem

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{s}{\sqrt{n}}$ (a)

And on this case we have that ME =0.35 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025;0;1)", and we got $z_{\alpha/2}=1.960$ , replacing into formula (b) we got:

$n=(\frac{1.960(2.25)}{0.35})^2 =158.76 \approx 159$

So the answer for this case would be n=159 rounded up to the nearest integer

3 0

3 years ago

If f(x)=4x-7, find X if f(x) = -3.

Minchanka [31]

Well if you download the app photo math and take a photo of it. It will solve it for you

7 0

3 years ago