Two numbers are respectively 40% and 60% more than a third number. The ratio of the two numbers is:

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

The conditional relative frequency table below was generated by column using frequency table data comparing the number of calori

Rudik [331]

There is an association because the value 0.15 is not similar to the value 0.55

For the nutritionist to determine whether there is an association between where food is prepared and the number of calories the food contains, there must be an association between two categorical variables.

The conditions that satisfy whether there exists an association between conditional relative frequencies are:

1. When there is a bigger difference in the conditional relative frequencies, the stronger the association between the variables.

2. When the conditional relative frequencies are nearly equal for all categories, there may be no association between the variables.

For the given conditional relative frequency, we can see that there exists a significant difference between the columns of the table in the picture because 0.15 is significantly different from 0.55 and 0.85 is significantly different from 0.45

We can conclude that there is an association because the value 0.15 is not similar to the value 0.55

5 0

3 years ago

Read 2 more answers

10 times The sum of half a numberand six is eight

GuDViN [60]

The numerical form of this worded expression is:

10(1/2n + 6)=8

4 0

3 years ago

What is real world meaning

grin007 [14]

The definition of a real-world equation is an equation that could perhaps occur in real life, for things like construction.

⭐ Please consider brainliest! ⭐

✉️ If any further questions, inbox me! ✉️

7 0

3 years ago

Please help it would be much appreciated!!

AlekseyPX

Answer:

a) P) 0.25 = 1/4 both

b) P) 0.75 = 3/4 one

c) P) 0.25 = 1/4 none

Step-by-step explanation:

4 routes to D + H

6 routes to H + S

= D H S

4 | 6

- 2 | -3

= 2 | 3 = route 1 = 2/4 and route 2 = 3/6

= 1/2 route 1 and 1/2 route 2

Answer a ) = 1/2 x 1/2 = 0.25 = 1/4 = 0.25 probability

Answer b) = 1- (1/2 x 1/2) = 1- 0.25 = 3/4 = 0.75 probability

Answer c) = 1/2 x 1/2 = 0.25 = 1/4 = 0.25 probability

3 0

3 years ago