Are the leap years divisible by 2

Factor the expression (x+4)^2-4y^5(x+4)+4y^10

Kamila [148]

If you factor this,
it is (x+4-2y^5)^2

6 0

2 years ago

PLEASE SHOW WORK ILL GIVE BRAINLIEST DUE TODAY!!!

lana [24]

Answer:

1.) 169

2.) 63

3.) 50

4.) 221

5.) 6

6.) 501

7.)11

8.) 9

Step-by-step explanation:

sorry i dont have time for the explanation. :( i hope i helped you still

4 0

2 years ago

What number makes 3 and 71 divisible by 9?

Snezhnost [94]

3 only
7 only 
1 only 
1, 4, and 7 
do you mean which digit is added to 371 so that it is divisible by 3 
test for 3, sum of digits divisible by 3 
3 + 7 + 1 = 11 
if you add 3, 11 + 3 = 14 not divisible by 3 
if you add 7, 11+ 7 = 18 divisible by 3 
if you add 1, 11+ 1 = 12 divisible by 3 
if you add 1, 4, 7 divisible by 3

4 0

2 years ago

A certain test preparation course is designed to help students improve their scores on the LSAT exam. A mock exam is given at th

Valentin [98]

Answer:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

The mean calculated for this case is $\bar X=12.8$

The sample deviation calculated $s=4.324 \approx 4.3$

$12.8-4.604\frac{4.324}{\sqrt{5}}=3.896$

$12.8+ 4.604\frac{4.324}{\sqrt{5}}=21.704$

So on this case the 99% confidence interval would be given by (3.896;21.704)

Step-by-step explanation:

Data: 10,9,20,13,12

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:

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

In order to calculate the mean and the sample deviation we can use the following formulas:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

The mean calculated for this case is $\bar X=12.8$

The sample deviation calculated $s=4.324$

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=5-1=4$

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: "=-T.INV(0.005,4)".And we see that $t_{\alpha/2}=4.604$