What number has 2 hundreds and the tens digit is 9 more than the ones digit

HELPPPPP ASAP!!!! Thx!! and NOOO FILESSSS!! it's on KHAN ACADEMY!!

Black_prince [1.1K]

Answer:

$32$

Step-by-step explanation:

$x=\dfrac{180-116}{2}=\dfrac{64}{2}=32$

7 0

3 years ago

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard devia

Arturiano [62]

Answer:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (3)

$n=(\frac{2.58(54.5)}{5})^2 =790.846 \approx 791$

So the answer for this case would be n=791 rounded up to the nearest integer

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".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (2)

And on this case we have that ME =+5 and we are interested in order to find the value of n, if we solve n from equation (2) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (3)

$n=(\frac{2.58(54.5)}{5})^2 =790.846 \approx 791$

So the answer for this case would be n=791 rounded up to the nearest integer

4 0

3 years ago

Find an angle between 0 and 2pi that is coterminal with the following angle.<br><br> 32pi/9

never [62]

<span>To do these you will be adding or subtracting  2pi (or integer multiples of .

Since the given angles are in fraction form, it will help to have 2pi  in fraction form, 2pi=10/5=6pi/3=4pi/2=18pi/9 NOTE: this>(/) stands for over like 1 over 2 EX. 1/2

too, so the addition/subtraction is easier.

Hint: When deciding if you have a number between 0 and 2pi, compare it to the fraction version of 2pi that you've been adding/subtracting.

For 17pi/5...
First we can see that 17pi/5 is more than 10pi/5 (aka 2pi). So we need to start subtracting: 17pi/5 - 10pi/5 = 7pi/5

Now we have a number between 0 and 10pi/5. So 7pi/5 is the co-terminal angle between 0 and 2pi.

I'll leave the others for you to do. Just remember that you might have to add or subtract  multiple times before you get a number between 0 and 2pi.
P.S don't add or subtract at all if the number starts out between 0 and 2pi.</span>

5 0

3 years ago

Help please?? If you deposit $750 in an account that pays 8% annual interest compounded continuously, what will the balance be a

Stella [2.4K]

The formula of a continuous compound interest is
A=p e^rt
A the balance?
P present value 750
E constant
R interest rate 0.08
T time 5 years
A=750×e^(0.08×5)
A=1,118.87

7 0

3 years ago

Help me out with this please

kakasveta [241]

Answer:

i think it is a but not shour

Step-by-step explanation:

7 0

3 years ago