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3 years ago

Help on number 5 please

Mathematics

1 answer:

Llana [10]3 years ago

5 0

What is the answer I can help but first what is the answer?

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A researcher compares the effectiveness of two different instructional methods for teaching electronics. A sample of 138 student

yan [13]

Answer:

The 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).

Step-by-step explanation:

The (1 - α)% confidence interval for the difference between population means is:

$CI=(\bar x_{1}-\bar x_{2})\pm z_{\alpha/2}\times \sqrt{\frac{\sigma^{2}_{1}}{n_{1}}+\frac{\sigma^{2}_{2}}{n_{2}}}$

The information provided is as follows:

$n_{1}= 138\\n_{2}=156\\\bar x_{1}=61\\\bar x_{2}=64.6\\\sigma_{1}=18.53\\\sigma_{2}=13.43$

The critical value of z for 98% confidence level is,

$z_{\alpha/2}=z_{0.02/2}=2.326$

Compute the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 as follows:

$CI=(\bar x_{1}-\bar x_{2})\pm z_{\alpha/2}\times \sqrt{\frac{\sigma^{2}_{1}}{n_{1}}+\frac{\sigma^{2}_{2}}{n_{2}}}$

$=(61-64.6)\pm 2.326\times\sqrt{\frac{(18.53)^{2}}{138}+\frac{(13.43)^{2}}{156}}\\\\=-3.6\pm 4.4404\\\\=(-8.0404, 0.8404)\\\\\approx (-8.04, 0.84)$

Thus, the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).

5 0

3 years ago

Which of the following expressions is equivalent to the expression 2(7x+3)

Ira Lisetskai [31]

Answer:

14x+6 and (7x+7)+(3+3)

Step-by-step explanation:

4 0

3 years ago

Double a number is equal to the number decreased by five?

kotegsom [21]

2n=n-5 subtract n from both sides

n=-5

check...

2(-5)=(-5)-5

-10=-10

6 0

3 years ago

Jonna needs to travel 496 miles in 8 hours. How fast does she need to go in order to reach her destination on time?

Mkey [24]

Answer:62

Step-by-step explanation:

3 0

3 years ago

Which operation results in a binomial? (3y ^ 6 + 4) (9y ^ 12 - 12y ^ 6 + 16)

AleksAgata [21]

Step-by-step explanation:

Given the expression, $(3y ^ 6 + 4) (9y ^ {12} - 12y ^ 6 + 16)$ , we want to know which sign placed in between the two polynomial will produce a binomial.

Using a plus (+) sign to check:

$= (3y ^ 6 + 4) + (9y ^ {12} - 12y ^ 6 + 16)\\= (3y ^ 6 + 4) + (9y ^ {12} - 12y ^ 6 + 16)\\collect \ like \ terms\\= 9y^{12} +3y^6 - 12y^6 + 16+ 4\\= 9y^{12} - 9y^6 + 20\\$

From the gotten value, it can be seen that the resulting answer produces 3 terms, showing that it results in a trinomial instead of binomial.

Using a plus (-) sign to check:

$= (3y ^ 6 + 4) - (9y ^ {12} - 12y ^ 6 + 16)\\= 3y ^ 6 + 4 - 9y ^ {12} + 12y ^ 6 - 16\\collect \ like \ terms\\= -9y^{12} +3y^6 +12y^6 + 4-16\\= -9y^{12} +15y^6 -12\\$

From the gotten value, it can be seen that the resulting answer produces 3 terms, showing that it results in a trinomial instead of binomial.

Hence none of the operations given results in a binomial

3 0

2 years ago