Which of the following is the best estimate for the mass of an adult rabbit?

Use the quadratic formula to solve x2 + 9x + 10 = 0.<br> What are the solutions to the equation?

vampirchik [111]

Answer:

$\large\boxed{x=\dfrac{-9\pm\sqrt{41}}{2}}$

Step-by-step explanation:

$\text{The quadratic formula of}$

$ax^2+bx+c=0$

$\text{If}\ b^2-4a0,\ \text{then the equation has two solutions}\ x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}\\=========================================$

$\text{We have}\ x^2+9x+10=0\\\\a=1,\ b=9,\ c=10\\\\\text{substitute:}\\\\b^2-4ac=9^2-4(1)(10)=81-40=41>0\qquad _{\text{two solutions}}\\\\\sqrt{b^2-4ac}=\sqrt{41}\\\\x=\dfrac{-9\pm\sqrt{41}}{2(1)}=\dfrac{-9\pm\sqrt{41}}{2}$

5 0

3 years ago

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A new television set was recently purchased for the common room in a residence hall for $436.80 including tax the tax rate is 4%

garri49 [273]

Answer:

The price of the television before taxes is $420

Step-by-step explanation:

* Lets explain how to solve the problem

- The purchased price = cost price + taxes

- A new television set was recently purchased for the common room

in a residence hall for $436.80

- This price including tax

- The tax rate is 4%

- We need to find the price of the television before taxes

* <em>Lets solve the problem</em>

- Assume that the price of the television before tax is 100%

∵ The tax rate is 4%

∵ The price after tax = price before tax + tax

∵ The price before tax = 100%

∴ The price after tax = 100% + 4% = 104%

∵ 104% equivalent to $436.80

∴ 100 ⇒ ?

104 ⇒ 436.80

- <em>By using cross multiplication</em>

∴ ? = $\frac{(436.80)(100)}{104}=420$

∴ The price of the television before taxes is $420

6 0

3 years ago

Heights of men have a bell-shaped distribution, with a mean of 176 cm and a standard deviation of 7 cm. Using the Empirical Rule

Vaselesa [24]

Answer:

a) 68% of the men fall between 169 cm and 183 cm of height.

b) 95% of the men will fall between 162 cm and 190 cm.

c) It is unusual for a man to be more than 197 cm tall.

Step-by-step explanation:

The 68-95-99.5 empirical rule can be used to solve this problem.

This values correspond to the percentage of data that falls within in a band around the mean with two, four and six standard deviations of width.

<em>a) What is the approximate percentage of men between 169 and 183 cm? </em>

To calculate this in an empirical way, we compare the values of this interval with the mean and the standard deviation and can be seen that this interval is one-standard deviation around the mean:

$\mu-\sigma=176-7=169\\\mu+\sigma=176+7=183$

Empirically, for bell-shaped distributions and approximately normal, it can be said that 68% of the men fall between 169 cm and 183 cm of height.

<em>b) Between which 2 heights would 95% of men fall?</em>

This corresponds to ±2 standard deviations off the mean.

$\mu-2\sigma=176-2*7=162\\\\\mu+2\sigma=176+2*7=190$

95% of the men will fall between 162 cm and 190 cm.

<em>c) Is it unusual for a man to be more than 197 cm tall?</em>

The number of standard deviations of distance from the mean is

$n=(197-176)/7=3$

The percentage that lies outside 3 sigmas is 0.5%, so only 0.25% is expected to be 197 cm.

It can be said that is unusual for a man to be more than 197 cm tall.

3 0

3 years ago

What is the final amount if 931 is decreased by 1% followed by a 1% increase?

earnstyle [38]

Answer:

930.91

Step-by-step explanation:

931 x 99% = 921.69

921.69 x 101% = 930.9069

8 0

3 years ago

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a 18 ft tall statue standing next to a globe casts a 12 ft shadow. Of the globe casts a shadow that is 2 ft ling, then how tall

Igoryamba

<h3>Answer:</h3>

3 ft

<h3>Step-by-step explanation:</h3>

The statue's height is 1.5 times the length of its shadow, so we expect the same relationship for the globe.

... 1.5 × 2 ft = 3 ft

_____

<em>Comment on the problem</em>

As a practical matter, with the sun high enough in the sky to cast a shadow shorter than the object's height, it will be quite difficult to measure the length of the shadow of the point at the top of the globe. The shadow of other parts of the globe will interfere.

4 0

3 years ago