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katen-ka-za [31]

3 years ago

11

A treatment is administered to a sample of n = 9 individuals selected from a population with a mean of m = 80 and a standard dev

iation of s = 12. after treatment, the effect size is measured by computing cohen's d, and a value of d = 0.50 is obtained. based on this information, what is the mean for the treated sample?

1 answer:

kupik [55]3 years ago

5 0

Cohen's d is calculated according to the formula:
d = (mean difference) / standard deviation
0.5 = mean difference / 12
Therefore, mean difference = 6
Since we have a population mean of 80, the sample mean must be 80 + 6 = 86.

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Country Financial, a financial services company, uses surveys of adults age and older to determine if personal financial fitness

Yakvenalex [24]

Complete Question

Country financials, a financial services company, uses surveys of adults age 18 and older to determine if personal financial fitness is changing over time. In February 2012, a sample of 1000 adults showed 410 indicating that their financial security was more that fair. In Feb 2010, a sample of 900 adults showed 315 indicating that their financial security was more than fair.

a

State the hypotheses that can be used to test for a significant difference between the population proportions for the two years.

b

What is the sample proportion indicating that their financial security was more that fair in 2012?In 2010?

c

Conduct the hypothesis test and compute the p-value.At a .05 level of significance what is your conclusion?

Answer:

a

The null hypothesis is $H_o : p_1 = p_2$

The alternative hypothesis is $H_a : p_1 \ne p_2$

b

in 2012 $\r p_1 =0.41$

in 2010 $\r p_2 =0.35$

c

The p-value is $p-value = 0.0072$

The conclusion is

There is sufficient evidence to conclude that the proportion of those indicating that financial security is more fair in Feb 2010 is different from the proportion of those indicating that financial security is more fair in Feb 2012.

Step-by-step explanation:

From the question we are told that

The sample size in 2012 is $n_1 = 1000$

The number that indicated that their finance was more than fail is k = 410

The sample size in 2010 is $n_2 = 900$

The number that indicated that their finance was more than fail is u = 315

The level of significance is $\alpha = 0.05[/ex]The null hypothesis is [tex]H_o : p_1 = p_2$

The alternative hypothesis is $H_a : p_1 \ne p_2$

Generally the sample proportion for 2012 is mathematically represented as

$\r p_1 = \frac{k}{n_1}$

=> $\r p_1 = \frac{410}{1000}$

=> $\r p_1 =0.41$

Generally the sample proportion for 2010 is mathematically represented as

$\r p_2 = \frac{u}{n_2}$

=> $\r p_2 = \frac{315}{900}$

=> $\r p_2 =0.35$

Generally the pooled sample proportion is mathematically represented as

$\r p = \frac{k + u }{n_1 + n_2}$

=> $\r p = \frac{410 + 315 }{1000+ 900}$

=> $\r p = 0.3816$

Generally the test statistics is mathematically represented as

$z = \frac{( \r p_1 - \r p_2 ) - 0}{\sqrt{\r p (1 - \r p ) ( \frac{1}{n_1} +\frac{1}{n_2} )} }$

$z = \frac{( 0.41 -0.35 ) - 0}{\sqrt{0.3816 (1 - 0.3816 ) ( \frac{1}{1000} +\frac{1}{900} )} }$

$z = \frac{( 0.41 -0.35 ) - 0}{\sqrt{0.3816 (1 - 0.3816 ) ( \frac{1}{1000} +\frac{1}{900} )} }$

$z = 2.688$

Generally the p- value is mathematically represented as

$p-value = 2 P(Z >2.688 )$

From the z -table

$P(Z > 2.688) = 0.0036$

So

$p-value = 2 *0.0036$

$p-value = 0.0072$

So from the p-value obtained we see that p-value < $\alpha$ so we reject the null hypothesis

Thus there is sufficient evidence to conclude that the proportion of financial security is more fair in Feb 2010 is different from the proportion of financial security is more fair in Feb 2012.

5 0

4 years ago

The Latin Club charted a bus to travel to and participate in a state competition. The cost for each adult to ride the bus was $2

Bumek [7]

<span>a+s =17 25a + 15s = 305</span>

7 0

3 years ago

To show what he learned about the properties of volume for solids, liquids and gases, Viktor wrote the following summary.

Brrunno [24]

The wrong statement in Viktor's summary is When a round solid ball is placed in a box, the ball takes the shape of the box

The matter has three main states which are

Solid
Liquid
Gas

These states define the way we interact and manipulate materials. For instance:

Liquids take the shape of the container that contains them. For example water, milk, soda, among others.

Solids have a defined shape and do not deform when manipulated or placed inside another container. For example, a round solid ball.

Gases generally do not have colors and their atoms are not organized so they do not have a definite shape and take the shape of their container. For example, the air in a balloon.

According to the above, the error in Viktor's summary is in the first phase, and the correct statement is A. because solids does not take the shape of its container.

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7 0

3 years ago

Need help on #15 ..........

Rama09 [41]

Just multiply man 2*4 2*3 1.5*4 and 1.5*3.

6 0

3 years ago

RSM QUESTION PLS HELP

AnnZ [28]

Answer:

K, P/R, M, A, T, N/B, I, O

Step-by-step explanation:

Just go up the y-axis

P and R have the same second coordinates,

So do N and B

4 0

3 years ago

Read 2 more answers