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STALIN [3.7K]
2 years ago
7

Researchers conducted a study to find out if there is a difference in the use of ereaders by different age groups. randomly sele

cted participants were divided into two age groupsin the to 29year-old group7% of the 628 surveyed use ereaders, while 11of the 2,309 participants 30 years old and older use ereaders(use subscripts let 1 16- to 29-year-old users , and 230 years old and
Mathematics
1 answer:
ikadub [295]2 years ago
4 0

No, there is significant difference in the use of e readers by different age groups.

Given sample 1 ( 29 years old) n_{1}=628, p_{1}=7%, sample 2( 30 years old)n_{2}=2309, p_{2}=0.11.

We have to first form hypothesis one null hypothesis and other alternate hypothesis.

H_{0}:π1-π2=0

H_{1}:π1-π2≠0

α=0.05

Difference between proportions p_{1}-p_{2}  =-0.04

p_{d}=0.07-0.11=-0.04

The pooled proportion needed to calculate standard error is:

p=(X_{1} -X_{2} )/(n_{1} +n_{2} )

=(44+254)/(628+2309)

=0.10146

The estimated standard error of difference between means is computed using the formula:

S_{p_{1} -p_{2} }=\sqrt{p(1-p)/m_{1}+p(1-p)/n_{2}  }

=\sqrt{0.101*0.899/628+0.101*0.899/2309}

=\sqrt{0.000143+0.00003}

=\sqrt{0.000173}

=0.01315

Z= Pd-(π1-π2)/S_{p_{1} -p_{2} }

=-0.04-0/0.013

=-3.0769

This test is a two tailed test so the p value for this test is calculated as (using z table)

p value:2 P(Z<-3.0769)

=2*0.002092

=0.004189

P value< significance level of 5%.

Hence there is enough evidence to show the claim that there is a significant difference in the use of e readers by different age groups.

Learn more about hypothesis at brainly.com/question/11555274

#SPJ4

Question is incomplete as it also includes:

Significance level of 5%.

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Chapman’s brickyard sells bricks and blocks. A brick costs $0.38 and a block costs $1.56. The brickyard filled a $24.80 order, w
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Answer:

number of bricks = 16 and number of blocks  = 12

Step-by-step explanation:

From given information it seems , we need to determine number of bricks and number of blocks.

lets assume number of bricks = x

and number of blocks = y

since total items in brickyard is 28

⇒  number of bricks + number of blocks = 28

⇒ x + y = 28         ----------------------- equation 1

Given that cost of 1 brick = $0.38  and cost of 1 block =$1.56

so cost of x bricks = cost of 1 brick × x = 0.38x

And cost of y blocks = cost of 1 block × y = 1.56y

total cost of 28 items order = $24.80

total cost of 28 items = cost of x bricks + cost of y blocks

⇒0.38x + 1.56y = 24.80 ----------------equation 2

Now we are having following two equations

x + y = 28         ----------------------- equation 1

0.38x + 1.56y = 24.80 ----------------equation 2

from equation 1 we get x = 28 - y , substituting this value of x in equation 2 we get

0.38(28 - y) + 1.56y =  24.80

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⇒1.18y = 24.80 - 10.64

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3 years ago
Using a sheet of graph paper, solve the following system of equations graphically. Be sure to show any work, use a straight edge
madam [21]

Answer:

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Step-by-step explanation:

Given system is

\left \{ {{x+y=0} \atop {x-y+2=0}} \right.

If we graph, the solution would be the interception point between these two lines, because each linear equation represents a line. The lines are attached.

In the graph, you can observe that the solution is the point (-1,1), that is x = -1 and y = 1.

Now, if we want to solve this system by another method, we can just sum both equations and solve for <em>x</em>

\left \{ {{x+y=0} \atop {x-y+2=0}} \right.

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Therefore, the solution is (-1,1)

4 0
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