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3 years ago

Can anybody help me please

Mathematics

2 answers:

FrozenT [24]3 years ago

6 0

4x + 5y = 13

Is (2, 1) a solution to the given linear equation?

4(2) + 5(1)

8 + 5 = 13

(2, 1) is a solution to the given linear equation

Is (-3, 0) a solution to the given linear equation

4(-3) + 5(0)

-12 + 0 = -12

(-3,0) is not a solution to the given linear equation

Is (0, 1) a solution to the given linear equation

4(0) + 5(1)

0 + 5 = 5

(0, 1) is not a solution to the given linear equation

Hope this helps :)

Alexus [3.1K]3 years ago

3 0

Answer:

The answers follow in order, yes, no, and no.

Step-by-step explanation:

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Find the area of the figure. Use 3.14 as π.

Karolina [17]

Answer: D. 94.25 in²

Step-by-step explanation:

To find the total area, we will break the shape up into two different parts.

[] The rounded part is 39.25 in². Let us assume the rounded part is exactly half of a circle.

Area of a circle:

A = πr²

Use 3.14 for pi:

A = (3.14)r²

Find the radius:

d / 2 = r, 10 / 2 = 5 in

Subsittue:

A = (3.14)(5)²

A = 78.5 in²

Divide by 2 since it is only half:

78.5 in² / 2 = 39.25 in²

[] The triangle is 55 in².

Area of a triangle:

A = b*h/2

A = 11 * 10 / 2

A = 110 / 2

A = 55 in²

[] Total area. We will add the two parts together.

55 in² + 39.25 in² = 94.25 in²

7 0

2 years ago

Read 2 more answers

A group of 50 New York psychology students got a mean score of 530 on the psychology GRE with a standard deviation of 80. These

lesantik [10]

Answer: No, New York students are not truly more nerdy than the California students.

Step-by-step explanation:

Since we have given that

Number of students in a group = 50

Mean score of New York psychology = 530

Mean score of California psychology = 515

Standard deviation = 80

So, we will find t-distribution first.

$t=\dfrac{x-\mu}{\dfrac{\sigma}{\sqrt{n}}}\\\\t=\dfrac{530-515}{\dfrac{80}{\sqrt{50}}}\\\\t=1.32$

Let α = 5% = 0.05

So, $t_{\alpha,2}=2.920$

Since t < t(critical value)

No, New York students are not truly more nerdy than the California students.

3 0

4 years ago

Marti is filling a 10– inch diameter ball with sand to make a medicine ball that can be used for exercising. To determine if the

Mice21 [21]

Answer:

Option A. $30\ pounds$

Step-by-step explanation:

step 1

Find the volume of the sphere ( medicine ball)

The volume is equal to

$V=\frac{4}{3}\pi r^{3}$

we have

$r=10/2=5\ in$ ----> the radius is half the diameter

Convert inches to feet

Remember that

1 ft=12 in

$r=5\ in=5/12\ ft$

assume

$\pi=3.14$

substitute

$V=\frac{4}{3}(3.14)(5/12)^{3}$

$V=0.3029\ ft^{3}$

step 2

Find the weight of the ball

Multiply the volume in cubic foot by 100

$0.3029*100=30.29\ pounds$

Round to the nearest pound

$30.29=30\ pounds$

6 0

3 years ago

Can someone please help me i don’t really understand these questions

Gemiola [76]

7) 9

8) 4

9) 20

Trust me

8 0

3 years ago

A sample of 200 observations from the first population indicated that x1 is 170. A sample of 150 observations from the second po

igor_vitrenko [27]

Answer:

a) For this case the value of the significanceis $\alpha=0.05$ and $\alpha/2 =0.025$ , we need a value on the normal standard distribution thataccumulates 0.025 of the area on each tail and we got:

$z_{\alpha/2} =1.96$

If the calculated statistic $|z_{calc}| >1.96$ we can reject the null hypothesis at 5% of significance

b) Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{170+110}{200+150}=0.8$

c) $z=\frac{0.85-0.733}{\sqrt{0.8(1-0.8)(\frac{1}{200}+\frac{1}{150})}}=2.708$

d) Since the calculated value satisfy this condition 2.708>1.96 we have enough evidence at 5% of significance that we have a significant difference between the two proportions analyzed.

Step-by-step explanation:

Data given and notation

$X_{1}=170$ represent the number of people with the characteristic 1

$X_{2}=110$ represent the number of people with the characteristic 2

$n_{1}=200$ sample 1 selected

$n_{2}=150$ sample 2 selected

$p_{1}=\frac{170}{200}=0.85$ represent the proportion estimated for the sample 1

$p_{2}=\frac{110}{150}=0.733$ represent the proportion estimated for the sample 2

$\hat p$ represent the pooled estimate of p

z would represent the statistic (variable of interest)

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

$\alpha=0.05$ significance level given

Concepts and formulas to use

We need to conduct a hypothesis in order to check if is there is a difference between the two proportions, the system of hypothesis would be:

Null hypothesis: $p_{1} = p_{2}$

Alternative hypothesis: $p_{1} \neq p_{2}$

We need to apply a z test to compare proportions, and the statistic is given by:

$z=\frac{p_{1}-p_{2}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{1}}+\frac{1}{n_{2}})}}$ (1)

a.State the decision rule.

For this case the value of the significanceis $\alpha=0.05$ and $\alpha/2 =0.025$ , we need a value on the normal standard distribution thataccumulates 0.025 of the area on each tail and we got:

$z_{\alpha/2} =1.96$

If the calculated statistic $|z_{calc}| >1.96$ we can reject the null hypothesis at 5% of significance

b. Compute the pooled proportion.

Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{170+110}{200+150}=0.8$

c. Compute the value of the test statistic.

z-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

Replacing in formula (1) the values obtained we got this:

$z=\frac{0.85-0.733}{\sqrt{0.8(1-0.8)(\frac{1}{200}+\frac{1}{150})}}=2.708$

d. What is your decision regarding the null hypothesis?

Since the calculated value satisfy this condition 2.708>1.96 we have enough evidence at 5% of significance that we have a significant difference between the two proportions analyzed.

5 0

3 years ago