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3 years ago

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Kevin spent 10 hours doing homework last week. This week he spent 15 hours doing homework. He says that he spent 150% more time

doing homework this week. Is he correct? Show your work to justify your decision.

1 answer:

agasfer [191]3 years ago

6 0

No he is wrong because 75% more time would be spent doing homework

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Some college graduates employed full-time work more than hours per week, and some work fewer than hours per week. We suspect tha

Alex_Xolod [135]

Answer:

a)Null hypothesis: $\mu =40$

Alternative hypothesis: $\mu \neq 40$

b) A Type of error I is reject the hypothesis that $\mu$ is equal to 40 when is fact $\mu is equal to 40c) We can commit a Type II Error, since by definition "A type II error is the non-rejection of a false null hypothesis and is known as "false negative" conclusion"Step-by-step explanation:Assuming this problem: "Some college graduates employed full-time work more than 40 hours per week, and some work fewer than 40 hours per week. We suspect that the mean number of hours worked per week by college graduates, [tex]\mu$ , is different from 40 hours and wish to do a statistical test. We select a random sample of college graduates employed full-time and find that the mean of the sample is 43 hours and that the standard deviation is 4 hours. Based on this information, answer the questions below"

Data given

$\bar X=43$ represent the sample mean

$\mu$ population mean (variable of interest)

s=4 represent the sample standard deviation

n represent the sample size

Part a: System of hypothesis

We need to conduct a hypothesis in order to determine if actual mean is different from 40 , the system of hypothesis would be:

Null hypothesis: $\mu =40$

Alternative hypothesis: $\mu \neq 40$

Part b

In th context of this tes, what is a Type I error?

A Type of error I is reject the hypothesis that $\mu$ is equal to 40 when is fact [tex]\mu is equal to 40

Part c

Suppose that we decide not to reject the null hypothesis. What sort of error might we be making.

We can commit a Type II Error, since by definition "A type II error is the non-rejection of a false null hypothesis and is known as "false negative" conclusion"

5 0

2 years ago

Read 2 more answers

Classify each system of equations as having a single solution, no solution, or infinite solutions.

mina [271]

To find what the answer is for this problem, we need to find out whether each of them have infinite, no, or single solutions. We can do this individually.

Starting with the first one, we need to convert both of the equations into slope-intercept form. y = -2x + 5 is already in that form, now we just need to do it to 4x + 2y = 10.

2y = -4x + 10
y = -2x +5

Since both equations give the same line, the first one has infinite solutions.

Now onto the second one. Once again, the first step is to convert both of the equations into slope-intercept form.

x = 26 - 3y becomes
3y = -x + 26
y = -1/3x + 26/3

2x + 6y = 22 becomes
6y = -2x + 22
y = -1/3 x + 22/6

Since the slopes of these two lines are the same, that means that they are parallel, meaning that this one has no solutions.

Now the third one. We do the same steps.

5x + 4y = 6 becomes
4y = -5x + 6
y = -5/4x + 1.5

10x - 2y = 7 becomes
2y = 10x - 7
y = 5x - 3.5

Since these two equations are completely different, that means that this system has one solution.

Now the fourth one. We do the same steps again.

x + 2y = 3 becomes
2y = -x + 3
y = -0.5x + 1.5

4x + 8y = 15 becomes
8y = -4x + 15
y = -1/2x + 15/8

Once again, since these two lines have the same slopes, that means that they are parallel, meaning that this one has no solutions.

Now the fifth one.

3x + 4y = 17 becomes
4y = -3x + 17
y = -3/4x + 17/4

-6x = 10y - 39 becomes
10y = -6x + 39
y = -3/5x + 3.9

Since these equations are completely different, there is a single solution.

Last one!

x + 5y = 24 becomes
5y = -x + 24
y = -1/5x + 24/5

5x = 12 - y becomes
y = -5x +12

Since these equations are completely different, this system has a single solution.

8 0

3 years ago

Of the 100 entries in a costume contest, 39 entrants were dressed as heroes and 45 entrants were wearing a mask. If 21 entrants

ehidna [41]

Correct question with correct options has been attached

Answer:

37

Step-by-step explanation:

Let C represent those dressed as heroes and let B represent those wearing mask

Thus;

n(C) = 39

n(D) = 45

We are told that 21 entrants were dressed as heroes wearing a mask.

Thus; n(C n D) = 21

We are also told that there were a total of 100 entries.

Thus, n(T) = 100

Now, number of entrants neither dressed as heroes nor wearing a mask is given by;

n(T) - n(C u D)

n(C u D) = n(C) + n(D) - n(C n D)

n(C u D) = 39 + 45 - 21

n(C u D) = 63

Thus;number of entrants neither dressed as heroes nor wearing a mask is: 100 - 63 = 37

3 0

3 years ago

I need help it's geometry

nekit [7.7K]

Step-by-step explanation:

$\sin(45) = \frac{x}{5} \\ \frac{1}{ \sqrt{2} } = \frac{x}{5} \\ x = \frac{5}{ \sqrt{2} } = 3.535$

$\sin(45) = \frac{y}{5} \\ y = \frac{5}{ \sqrt{2} } = 3.535$

3 0

2 years ago

Read 2 more answers

During a test period, an experimental group of 10 vehicles using an 85 percent ethanol-gasoline mixture showed mean CO2 emission

Aleksandr-060686 [28]

Answer:

Probably unequal ( B )

Step-by-step explanation:

<u>experimental group = 10</u>

using 85% ethanol gasoline

mean = 240 pounds per 100 miles

standard deviation = 20 pounds

<u>control group = 14 vehicles </u>

using regular gasoline

mean = 252 pounds per 100 miles

standard deviation = 15 pounds

comparing the sample variance of each group shows that they are probably unequal using the equation below

Variance for a sample set of data = ∑ ( x - X ) ^2 / n - 1

where n = number of events

X = mean value

x = value of events

8 0

2 years ago