Jordan found cloth for $7.50 per yard. How much would his total cost be if he needed 12 yards of cloth?

wlad13 [49]

Answer: Choice A

Raising something to the 1/4th power is the same as applying the 4th root to that expression. Raising an expression to the 1/n power is the same as applying the nth root.

Rule:
$x^{1/n} = \sqrt[n]{x}$
(if the text is too small it basically says x to the (1/n) = square root with a small 'n' all over x)

4 0

3 years ago

Solve for the variable 9b+4−8b=7 b = ?

timurjin [86]

The answer is 3
B+4=7
B=7-4
B=3

7 0

3 years ago

Derive the equation of the parabola with a focus at (−2, 4) and a directrix of y = 6. Put the equation in standard form.

zlopas [31]

Sketch a graph so you can find the vertex and determine if the parabola is horizontal or vertical. When i graph (-2,4) and then y=6, I find the middle is (-2,5) so that will be the vertex. The distance to the vertex is -1 so 4p=-4.
My formula is (x-h)^2=4p(y-k), now just plug in numbers. You should end up with (x+2)^2=-4(y-5).
Some instructors want you to write (y-k)=1/(4p)(x-h)^2 which is the same thing, so check to see which one you should be using.

3 0

4 years ago

You need to compute the a 90% confidence interval for the population mean. How large a sample should you draw to ensure that the

RSB [31]

Answer:

The sample size required is 102.

Step-by-step explanation:

The (1 - α)% confidence interval for population mean μ is:

$CI=\bar x\pm z_{\alpha/2}\times\frac{\sigma}{\sqrt{n}}$

The margin of error for this interval is:

$MOE= z_{\alpha/2}\times\frac{\sigma}{\sqrt{n}}$

Given:

σ = 9.2

(1 - α)% = 90%

MOE = 1.5

The critical value of z for 90% confidence level is:

$z_{0.10/2}=1.645$

*Use a z-table.

Compute the value of n as follows:

$MOE= z_{\alpha/2}\times\frac{\sigma}{\sqrt{n}}$

$n=[\frac{z_{\alpha/2}\times \sigma}{MOE}]^{2}$

$=[\frac{1.645\times 9.2}{1.5}]^{2}\\=101.795\\\approx102$

Thus, the sample size required is 102.

5 0

3 years ago

Wendy's restaurant has been recognized for having the fastest average service time among fast food restaurants. In a benchmark s

VikaD [51]

Answer:

(a) 0.2885

(b) 0.0736

(c) 0.0468

Step-by-step explanation:

The exponential distribution of Wendy's service time is given by:

P(x) = [exp (-x/μ)]/μ............................................................................ (1)

P(x) = Probability function

x = Service time, in minute

μ = average service team, in minute, 2.2 minutes

(a) x= 1, substituting into equation (1) we have:

P(1) = [exp (-1/2.2)]/2.2

= 0.6347/2.2

= 0.2885

(b) x₁ = 0.5 minutes

x₂ = 1 minute

P (0.5<x<1) = P(0.5) -P(1) ----------------------------------------------- (2)

From (a), P (1) = 0.2885

P(0.5) =P(1) = [exp (-0.5/2.2)]/2.2

= 0.7967/2.2

= 0.3621

Substituting into (2), we have :

P (0.5<x<1) = 0.3621 -0.2885

= 0.0736

(c) P(5) = [exp (-5/2.2)]/2.2

= 0.1030/2.2

= 0.0468

7 0

3 years ago