Will mark brainliest for whoever answers

HELP ASAP!! No links or photos please. Don't answer if you don't know it

yuradex [85]

Answer:

b no

Step-by-step explanation:

c^2 = $\sqrt{a {}^{2} +b {}^{2}} 9 + 25 \: is \: not =81$

7 0

2 years ago

What is between 3/8 in a number line

storchak [24]

Okay I hope this is what you mean. so if you are saying what is between the numbers 3 and 8 we can make an inequality which will cover all the small decimals between the numbers.

There are 2 different equalities that I'm not sure which one you want.

so the first one would be
$3 \leqslant x \leqslant 8$
x is just the variable I chose for this. Now this inequality means that both 3 and 8 are solutions to the problem. x represent all the little numbers in between so to test your answers just plugin the number you're testing in for x. Since 3 is the lowest number it will have a less than or equal to (in this case) sign and 8 is the greatest so that's why the open/greater side is facing the 8. It reads 3 is less than or equal to x and x is less than or equal to 8.

If you meant all number in between 3 and 8 not include either of those numbers than the inequality would be
$3 < x < 8$
In this case all the numbers between 3 and 8 are solutions but 3 and 8 will not be solutions. the line under the symbol means it includes the number which come before or after it. The inequality reads 3 is less than x which is less than 8. You can also plugin in an answer to test it in place of x.

If you have any questions or it turns out you meant somthing else please tell me and I'll be happy to help, sorry if this isn't what you meant in the question.

3 0

2 years ago

Scores on the SAT Mathematics test are believed to be normally distributed. The scores of a simple random sample of five student

AysviL [449]

Answer:

The mean calculated for this case is $\bar X=584$

And the 95% confidence interval is given by:

$584-2.776\frac{86.776}{\sqrt{5}}=476.271$

$584+2.776\frac{86.776}{\sqrt{5}}=691.729$

So on this case the 95% confidence interval would be given by (476.271;691.729)

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:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (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 $\bar X=584$

The sample deviation calculated $s=86.776$

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 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a tabel to find the critical value. The excel command would be: "=-T.INV(0.025,4)".And we see that $t_{\alpha/2}=2.776$