What’s the solution

A study was conducted to estimate the difference in the mean salaries of elementary school teachers from two neighboring states.

umka21 [38]

Answer:

$(28900-30300) -2.07 \sqrt{\frac{2300^2}{10} +\frac{2100^2}{14}} = -3301.70$

$(28900-30300) +2.07 \sqrt{\frac{2300^2}{10} +\frac{2100^2}{14}} = 501.698$

The confidence interval would be $-3301.70 \leq \mu \leq 501.698$ and since the confidence interval contains the value of 0 we don't have enough evidence to conclude that the difference between the two states for the salary of teachers are significantly different.

Step-by-step explanation:

We have the following info given by the problem

$\bar X_1 = 28900$ the sample mean for the salaries of teachers in Indiana

$s_1 = 2300$ the sample deviation for the salary of teachers in Indiana

$n_1 =10$ the sample size from Indiana

$\bar X_2 = 30300$ the sample mean for the salaries of teachers in Michigan

$s_2 = 2100$ the sample deviation for the salary of teachers in Michigan

$n_2 =14$ the sample size from Michigan

We want to find a confidence interval for the difference in the two means and the formula for this case is given by;

$(\bar X_1 -\bar X_2) \pm t_{\alpha/2}\sqrt{\frac{s^2_1}{n_1} +\frac{s^2_2}{n_2}}$

The degrees of freedom for this case are:

$df = n_1 +n_2 -2= 10+14-2 =22$

The confidence is 95%so then the significance is $\alpha=0.05$ and the $\alpha/2 =0.025$ , we need to find a critical value in the t distribution with 22 degrees of freedom who accumulates 0.025 of the area on each tail and we got:

$t_{\alpha/2}= 2.07$

And now replacing in the formula for the confidence interval we got:

$(28900-30300) -2.07 \sqrt{\frac{2300^2}{10} +\frac{2100^2}{14}} = -3301.70$

$(28900-30300) +2.07 \sqrt{\frac{2300^2}{10} +\frac{2100^2}{14}} = 501.698$

The confidence interval would be $-3301.70 \leq \mu \leq 501.698$ and since the confidence interval contains the value of 0 we don't have enough evidence to conclude that the difference between the two states for the salary of teachers are significantly different.

6 0

2 years ago

Lisa drank 4/5

vesna_86 [32]

Answer:

12/15 + 10/15= 1 whole and 7/15

Step-by-step explanation:

5 0

2 years ago

The Hickory Stick has a selection of 3 meats and 6 vegetables. How many different selections of one meat and one vegetable are p

valentina_108 [34]

The different selections of one meat and one vegetable are possible are 18 selections.

Since the Hickory Stick has a selection of 3 meats and 6 vegetables, the number of ways we can select one meat out of 3 is ³C₁ = 3.

Also, the number of ways we can select one vegetable out of 6 is ⁶C₁ = 6.

So, the total number of selections of one meat and one vegetable is ³C₁ × ⁶C₁ = 3 × 6

= 18 selections

So, the different selections of one meat and one vegetable are possible are 18 selections.

Learn more about combination here:

brainly.com/question/19341024

7 0

1 year ago

Factor sec^2x-secx+tan^2x

marysya [2.9K]

Answer:

sec²(x) - sec(x) + tan²(x) = (sec(x) - 1)(2sec(x) + 1)

Step-by-step explanation:

sec²(x) - sec(x) + tan²(x) =

= sec²(x) - sec(x) + [sec²(x) - 1]

= sec²(x) - sec(x) + [(sec(x) + 1)(sec(x) - 1)]

= sec(x)[sec(x) - 1] + [(sec(x) + 1)(sec(x) - 1)]

= (sec(x) - 1)(sec(x) + sec(x) + 1)

= (sec(x) - 1)(2sec(x) + 1)

6 0

2 years ago

The histograms below show the heights (in meters) of the tallest buildings in China and the United States.

gregori [183]

Answer:

A and B

Step-by-step explanation:

This is correct on khan academy!

8 0

2 years ago

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