How much more intense is an earthquake that measures 7.5 on the Richter scale than one that measures 6.2?

A student researcher compares the heights of American students and non-American students from the student body of a certain coll

Nonamiya [84]

Answer:

The 90% confidence interval for the difference between means is (4.189, 8.011).

The point estimate is the difference between sample means and has a value of Md=6.1.

Step-by-step explanation:

We have to calculate a 90% confidence interval for the difference between means.

The sample 1 (American students), of size n1=12 has a mean of 69.4 and a standard deviation of 2.79.

The sample 2 (non-American students), of size n2=17 has a mean of 63.3 and a standard deviation of 3.22.

The difference between sample means is Md=6.1.

$M_d=M_1-M_2=69.4-63.3=6.1$

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

$s_{M_d}=\sqrt{\dfrac{\sigma_1^2}{n_1}+\dfrac{\sigma_2^2}{n_2}}=\sqrt{\dfrac{2.79^2}{12}+\dfrac{3.22^2}{17}}\\\\\\s_{M_d}=\sqrt{0.649+0.61}=\sqrt{1.259}=1.12$

The critical t-value for a 90% confidence interval is t=1.703.

The margin of error (MOE) can be calculated as:

$MOE=t\cdot s_{M_d}=1.703 \cdot 1.12=1.911$

Then, the lower and upper bounds of the confidence interval are:

$LL=M_d-t \cdot s_{M_d} = 6.1-1.911=4.189\\\\UL=M_d+t \cdot s_{M_d} = 6.1+1.911=8.011$

The 90% confidence interval for the difference between means is (4.189, 8.011).

4 0

3 years ago

A large loan company specializes in making automobile loans for used cars. The board of directors wants to estimate the average

diamong [38]

Answer:

z-interval: (-1.64, 1.64)

90% Confidence interval: (7954,8446)

Step-by-step explanation:

We are given the following in the question:

Sample mean, $\bar{x}$ = $8,200

Sample size, n = 225

Alpha, α = 0.10

Sample standard deviation, s = $750

90% Confidence interval:

$\mu \pm z_{critical}\dfrac{\sigma}{\sqrt{n}}$

Putting the values, we get,

$z_{critical}\text{ at}~\alpha_{0.10} = \pm 1.64$

z-interval: (-1.64, 1.64)

$8200 \pm 1.64(\dfrac{750}{\sqrt{25}} ) = 8200 \pm 246 = (7954,8446)$

(7954,8446) is the required confidence interval.

4 0

3 years ago

What monomial do you have to raise to the power of 2 to get the given monomial? What monomial do you have to raise to the power

Mamont248 [21]

Answer:

x^3y^6

Step-by-step explanation:

x^6y^12

Take the square root:-

= (x^6)^1/2 (y^12)^1/2

= x^3y^6 (answer)

Checking to see if this is correct:-

(x^3y^6)^2

= x^(3*2)y^(6*2)

= x^6y^12

4 0

3 years ago

Which of the following is the standard form of y =3/7 x-1 a)3/7x-y=1 b) y-3/7x= - 1 c) 7y-3x= -7 d) 3x - 7y= 7

padilas [110]

Answer:

d)

Step-by-step explanation:

the general form is ax + by = c

6 0

3 years ago

Which of the following is the solution to the equation below?<br> 15 = q3<br> A 3<br> B 5<br> C 45

Vsevolod [243]

Hiya the answer to your maths question is B :) xx

6 0

3 years ago