Help ?? Is it true of false ??

The formula for the area of a rhombus is A = a equals StartFraction one-half EndFraction d 1 d 2.d1d2, where d1 and d2 are the l

Strike441 [17]

Answer:

$\large\boxed{d_1=\dfrac{2A}{d_2};\ d_2=\dfrac{2A}{d_1}}$

Step-by-step explanation:

$A=\dfrac{1}{2}d_1d_2\qquad\text{multiply both sides by 2}\\\\2A=2\!\!\!\!\diagup\cdot\dfrac{1}{2\!\!\!\!\diagup}d_1d_2\\\\2A=d_1d_2\to d_1d_2=2A$

$\text{For}\ d_1:\\\\d_1d_2=2A\qquad\text{divide both sides by}\ d_2\neq0\\\\d_1=\dfrac{2A}{d_2}\\\\\text{For}\ d_2:\\\\d_1d_2=2A\qquad\text{divide both sides by}\ d_1\neq0\\\\d_2=\dfrac{2A}{d_1}$

4 0

3 years ago

Read 2 more answers

Suppose the population of trout in a certain stretch of a river is 4000. In about how many years will the population of trout be

nadezda [96]

700=(4000)(0.65)x
4000 x 0.65
700=(2600)x
700=2600x
0.27=x
(rounded = 1 year)

3 0

3 years ago

The house has a form of a rectangle with one side two and a half times as long as the other side.

Studentka2010 [4]

Answer:

A. (x*2.5)*x

B. (32*2.5)*32=2560

Step-by-step explanation:

4 0

4 years ago

In a sample of nequals16 lichen specimens, the researchers found the mean and standard deviation of the amount of the radioacti

GuDViN [60]

Answer:

(a) The confidence level desired by the researchers is 95%.

(b) The sampling error is 0.002 microcurie per millilitre.

(c) The sample size necessary to obtain the desired estimate is 25.

Step-by-step explanation:

The mean and standard deviation of the amount of the radioactive element, cesium-137 present in a sample of n = 16 lichen specimen are:

$\bar x=0.009\\s=0.005$

Now it is provided that the researchers want to increase the sample size in order to estimate the mean μ to within 0.002 microcurie per millilitre of its true value, using a 95% confidence interval.

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

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

(a)

The confidence level is the probability that a particular value of the parameter under study falls within a specific interval of values.

In this case the researches wants to estimate the mean using the 95% confidence interval.

Thus, the confidence level desired by the researchers is 95%.

(b)

In case of statistical analysis, during the computation of a certain statistic, to estimate the value of the parameter under study, certain error occurs which are known as the sampling error.

In case of the estimate of parameter using a confidence interval the sampling error is known as the margin of error.

In this case the margin of error is 0.002 microcurie per millilitre.

(c)

The margin of error is computed using the formula:

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

The critical value of z for 95% confidence level is:

$z_{\alpha/2}=z_{0.05/2}=z_{0.025}=1.96$

*Use a z-table.

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

$0.002=1.96\times \frac{0.005}{\sqrt{n}}$

$n=[\frac{1.96\times 0.005}{0.002}]^{2}$

$=(4.9)^{2}\\=24.01\\\approx 25$

Thus, the sample size necessary to obtain the desired estimate is 25.

6 0

4 years ago

a circle pizza with a diameter of 10 inches. The pizza is in a square box with side lengths of 14 inches. In square inches, how

julsineya [31]

Answer:

117.45 in^2

Step-by-step explanation:

Given data

Diameter of pizza= 10in

Radius of pizza=10/2= 5in

Lenght of pizza box= 14in

Area of pizza= πr^2

A= 3.142*5^2

A= 3.142*25

A= 78.55 in^2

Area of pizza box= L^2

A= 14^2

A= 196 in^2

Hence the empty space is

=196-78.55

=117.45 in^2

5 0

3 years ago