An acidophilus culture containing 150 bacteria doubles in population every hour. predict the number of bacteria in 12 hours

Alex deposited x dollars into a new account that earned 8 percent annual interest, compounded annually. One year later Alex depo

djverab [1.8K]

Answer:

D

Step-by-step explanation:

Start by writing out w in terms of x. After one year, there is 1.08*x dollars in the account. x dollars are then deposited, giving us a total of 1.08*x + x (normally we would simplify this to 2.08 but looking at the answers this is not a good idea.) Next, multiply by 1.08 to account for the 2nd year's interest. This brings to total to w = 1.08(1.08*x + x) = (1.08^2)*x + 1.08*x. Factoring out x, we are left with w = (1.08^2 + 1.08) * x. Dividing both sides by (1.08^2 + 1.08), we are left with x = w/(1.08^2 + 1.08) so the answer is d.

8 0

3 years ago

For sin2x+cosx=0, use a double-angle or half-angle formula to simplify the equation and then find all solutions of the equation

Archy [21]

Answer:

Step-by-step explanation:

Given is a trignometric equation in x, as

$sin2x+cosx=0$

TO make it in one trig ratio, we can replace sin2x as 2sinx cosx

WE get now

$2sinxcosx+cosx=0\\$

$cosx(2sinx+1)=0\\cosx=0, sinx =-0.5\\$

Principal solution is $x=\frac{\pi}{2} , \frac{-\pi}{6}$

x = ±π/2 + 2kπ, where k is any integer or

x=±pi/6 +k pi, where k is any integer.

General solution is

4 0

3 years ago

A sample of size 6 will be drawn from a normal population with mean 61 and standard deviation 14. Use the TI-84 Plus calculator.

AVprozaik [17]

Answer:

$X \sim N(61,14)$

Where $\mu=61$ and $\sigma=14$

Since the distribution for X is normal then the distribution for the sample mean is also normal and given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

$\mu_{\bar X} = 61$

$\sigma_{\bar X}= \frac{14}{\sqrt{6}}= 5.715$

So then is appropiate use the normal distribution to find the probabilities for $\bar X$

Step-by-step explanation:

Previous concepts

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".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean". The letter $\phi(b)$ is used to denote the cumulative area for a b quantile on the normal standard distribution, or in other words: $\phi(b)=P(z$

Solution to the problem

Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:

$X \sim N(61,14)$

Where $\mu=61$ and $\sigma=14$

Since the distribution for X is normal then the distribution for the sample mean $\bar X$ is also normal and given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

$\mu_{\bar X} = 61$

$\sigma_{\bar X}= \frac{14}{\sqrt{6}}= 5.715$

So then is appropiate use the normal distribution to find the probabilities for $\bar X$

8 0

3 years ago

PLZ HELP <br> Which polynomial is written in standard form?

kotykmax [81]

I’m pretty sure it looks like it’s D

4 0

3 years ago

HELPPPPPP this is due tonight!!!!

laiz [17]

Answer:

(1) Commutative property

(2) Distributive property/Definition of addition

(3) Compatibility with addition/Existence of additive inverse/Modulative property

(4) Compatibility with multiplication/Associative property/Definition of division/Existence of additive inverse/Commutative and modulative properties/Result

Step-by-step explanation:

We proceed to solve algebraically and explain each step:

1) $4\cdot x +1 +x + 3 = -11$ GIven

2) $4\cdot x +x +1 + 3 = -11$ Commutative property

3) $(4+1)\cdot x +4 = -11$ Distributive property/Definition of addition

4) $5\cdot x +4 = -11$ Definition of addition

5) $5\cdot x +4 -4 = -11-4$ Compatibility with addition

6) $5\cdot x = -15$ Existence of additive inverse/Modulative property

7) $\frac{1}{5}\cdot (5\cdot x)= \frac{1}{5}\cdot (-15)$ Compatibility with multiplication

8) $x = - 3$ Associative property/Definition of division/Existence of additive inverse/Commutative and modulative properties/Result

Hence, we have the following answers:

(1) Commutative property

(2) Distributive property/Definition of addition

(3) Compatibility with addition/Existence of additive inverse/Modulative property

(4) Compatibility with multiplication/Associative property/Definition of division/Existence of additive inverse/Commutative and modulative properties/Result

6 0

3 years ago