Divide the 240g into the ratio 5:3:4?

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

2 years ago

What is the solution to the system of equations?

s344n2d4d5 [400]

Answer:

(3,2)

Step-by-step explanation:

Here's your given:

y = 4x - 10

y = 2

Because they both equal y, that means they equal each other:

2 = 4x - 10

Add 10 on both sides:

12 = 4x

Then, divide 4 on both sides:

3 = x

This represents the x coordinate.

Normally you would put this value into one of the equations to figure out y, but they already gave us that in the beginning:

y = 2

This represents the y coordinate.

Put the two values together to get: (3,2)

5 0

2 years ago

X=17-4y<br> y=x-2<br> answer by substitution

sashaice [31]

Answer:

x=5,y=3

Step-by-step explanation:

the first step is to decide whether you want to substitute y and find x, or substitute x and find y.

(it doesn't matter which way you will choose.If you do the math correctly you will get the correct answer,one way or another).

for example, let's substitute y into the first equation:

x=17-4*(x-2)

so now,we will organize the equation:

x+4x=17+8

5x=25/(÷5)

x=5

now we will substitute x with 5 in the second equation(or the first one,it doesn't matter)in order to find y:

y=5-2

y=3

3 0

3 years ago

Tyler selects one card from the three(4,5, and a King), and rolls a number cube. What is the probability that she selects the 5,

Svet_ta [14]

$\frac{1}{3}$ Answer:

2/9

Step-by-step explanation:

given that Tyler selects one card from the three(4,5, and a King), and rolls a number cube.

We find that A the event of selecting one card and B getting a number on rolling a number cube are independent events.

No of cards = 3

Prob of selecting 5 from 3 cards = $P(1,2,3, or 4) = \frac{2}{3}$

When rolling a number cube (assuming fair) there is equally likely for all numbers to appear from 1 to 6

Prob of getting 5 = $\frac{1}{6}$

Prob of getting less than 5 =

Since these two events are independent,

the probability that she selects the 5, and rolls a number less than 5

= Product of probabilities

= $\frac{1}{3}$ * $\frac{2}{3}$

= $\frac{2}{9}$

6 0

2 years ago

Maureen rolls a fair dice and flips a fair coin.

Taya2010 [7]

1/6 times 1/2 = 1/12

5 0

2 years ago

Divide the 240g into the ratio 5:3:4?​

Divide the 240g into the ratio 5:3:4?