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2 years ago

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Will ran four miles on his first day of training. The next day he ran one-third that distance. How far did he run the second day

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1 answer:

igomit [66]2 years ago

4 0

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Of 575 broiler chickens purchased from various kinds of food stores in different regions of a country and tested for types of ba

chubhunter [2.5K]

Answer:

a) $0.68 - 2.58 \sqrt{\frac{0.68(1-0.68)}{575}}=0.630$

$0.68 + 2.58 \sqrt{\frac{0.68(1-0.68)}{575}}=0.730$

And the 99% confidence interval would be given (0.630;0.730).

b) We are 99% confident that the true proportion of infected chickens are between 0.63 (63%) and 0.73 (73%)

c) For this case the answer would be No. Since all the required assumptions in order to construct the confidence interval are satisfied, so then the results can be assumed for all the population

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$p$ represent the real population proportion of interest

$\hat p =0.68$ represent the estimated proportion

n=575 is the sample size required (variable of interest)

$z$ represent the critical value for the margin of error

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{\hat p(1-\hat p)}{n}})$

Part a

The confidence interval would be given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 99% confidence interval the value of $\alpha=1-0.99=0.01$ and $\alpha/2=0.005$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=2.58$

And replacing into the confidence interval formula we got:

$0.68 - 2.58 \sqrt{\frac{0.68(1-0.68)}{575}}=0.630$

$0.68 + 2.58 \sqrt{\frac{0.68(1-0.68)}{575}}=0.730$

And the 99% confidence interval would be given (0.630;0.730).

Part b

We are 99% confident that the true proportion of infected chickens are between 0.63 (63%) and 0.73 (73%)

Part c

For this case the answer would be No. Since all the required assumptions in order to construct the confidence interval are satisfied, so then the results can be assumed for all the population

4 0

3 years ago

Which of the following shows an inconsistent system of equations?

77julia77 [94]

The third set is equivalent to

2x + y = 2
2x + y = -2

clearly inconsistent.

3 0

2 years ago

Which of the following methods can be used to find the derivative of y = arcsin x with respect to z ?

vfiekz [6]

Answer:

B) Ill only

Step-by-step explanation:

This is because y = arcsin x can be re-written as sin y = x, We then differentiate sin y = x implicitly with respect to z to obtain

d(siny)/dz = dx/dz

(cosy)dy/dz = dx/dz

dy/dz = (1/cosy)dx/dz

5 0

2 years ago

A rectangle has perimeter 28cm. Its area is 42sq.cm. Determine the dimensions of the rectangle. Include a diagram in your soluti

yawa3891 [41]

The dimensions of the rectangle are: b=9.65 cm and h=4.35 cm or b=4.35 cm and h= 9.65 cm.

<h3>Quadrilaterals</h3>

There are different types of quadrilaterals, for example, square, rectangle, rhombus, trapezoid, and parallelogram. Each type is defined accordingly to its length of sides and angles. For example, in a rectangle, the opposite sides are equal and parallel and their interior angles are equal to 90°.

The area of a rectangle is equal to base x height (A=bh). The perimeter of a geometric figure is the sum of its sides. Thus, for a rectangle, the perimeter is 2b+2h.

<h3>System of Linear Equations</h3>

System of linear equations is the given term math for two or more equations with the same variables. The solution of these equations represents the point at which the lines intersect.

The question gives:

Perimeter=28cm

Area= 42 cm²

If the perimeter is the sum of all sides of the rectangle, you have:

Perimeter= 2b+2h=28

If the area of the rectangle is 42cm², you have:

Area=bh=42 cm²

You can write a system of linear equations.

2b+2h=28 (1)

bh=42 (2)

From equation 2, you have $b=\frac{42}{h}$ . Then, you can replace it in equation 1.

$2*\frac{42}{h}+2h=28 \\ \\ 84+2h^2=28h\\ \\ 2h^2-28h+84=0 \; dividing\; by\; 2\\ \\ h^2-14h+42=0$

Now, you should solve the quadratic equation.

$h_{1,\:2}=\frac{-\left(-14\right)\pm \sqrt{\left(-14\right)^2-4\cdot \:1\cdot \:42}}{2\cdot \:1}$

$h_{1,\:2}=\frac{-\left(-14\right)\pm \:2\sqrt{7}}{2\cdot \:1}$

$h_1=\frac{-\left(-14\right)+2\sqrt{7}}{2\cdot \:1}=7+\sqrt{7}=9.65 cm$

$h_2=\frac{-\left(-14\right)-2\sqrt{7}}{2\cdot \:1}=7-\sqrt{7}=4.35cm$

If h1=9.65 cm, then $b_1=\frac{42}{9.65} =4.35 cm$ , and if h2=4.35 cm, then $b_1=\frac{42}{4.35} =9.65 cm$ .

Read more about the quadratic function here:

brainly.com/question/1497716

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8 0

1 year ago

David invested $340 in an account paying an interest rate of 2\tfrac{1}{8}2 8 1 % compounded continuously. Natalie invested $3

Nutka1998 [239]

Answer:

$53.83

Step-by-step explanation:

For David

David invested $340 in an account paying an interest rate of 2\tfrac{1}{8}2 8 1 % compounded continuously.

r = 2 1/8% = 17/8% = 2.125% = 0.02125

t = 17 years

P = $340

For Compounded continuously, the formula =

A = Pe^rt

A = Amount Invested after time t

P = Principal

r = interest rate

t = time

A = $340 × e^0.02125 × 17

A = $ 487.94

For Natalie

Natalie invested $340 in an account paying an interest rate of 2\tfrac{3}{4}2 4 3 % compounded quarterly.

r = 2 3/4 % = 11/4% = 2.75% = 0.0275

t = 17 years

P = $340

n = compounded quarterly = 4 times

Hence,

Compound Interest formula =

A = P(1 + r/n)^nt

A = Amount Invested after time t

P = Principal

r = interest rate

n = compounding frequency

t = time

A = $340 (1 + 0.0275/4) ^17 × 4

A = $ 541.77

After 17 years, how much more money would Natalie have in her account than David, to the nearest dollar?

This is calculated as

$541.77 - $ 487.94

= $53.83

Hence, Natalie would have in her account, $53.83 than David

4 0

2 years ago