What is the measure of the unknown segment? will mark brainliest !!

A random sample of 130 students is chosen from a population of 4,500 students. The mean IQ in the sample is 120, with a standard

barxatty [35]

Answer:

$120-2.614\frac{5}{\sqrt{130}}=118.85$

$120+2.614\frac{5}{\sqrt{130}}=121.15$

Step-by-step explanation:

Information given

$\bar X= 120$ represent the sample mean

$\mu$ population mean (variable of interest)

s=5 represent the sample standard deviation

n=130 represent the sample size

For this case we can't set a margin of error just with a % since they not specify 1.13% respect to something for this case we can omit this value

Confidence interval

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

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

The degrees of freedom are given by:

$df=n-1=130-1=129$

The Confidence level is 0.99 or 99%, the significance would be $\alpha=0.01$ and $\alpha/2 =0.005$ , and the critical value would be $t_{\alpha/2}=2.614$

And replacing we got:

$120-2.614\frac{5}{\sqrt{130}}=118.85$

$120+2.614\frac{5}{\sqrt{130}}=121.15$

3 0

3 years ago

A collection of quarters and dimes is worth $12.40. There are 67 coins in all.

padilas [110]

Let:
x= quarters
y= dimes

x+y=67
and
.25x+.10y=12.40

x=67-y

.25(67-y)+.10y=12.40
16.75-.25y+10y=12.40
16.75-.15y=12.40
Lets rearrange this:
-.15y+16.75=12.40
-16.75 -16.75
-.15y=-4.35
the negatives cancel out
.15y=4.35
.15 .15
y=29

Back to the original x=67-y
x=67-29
x=38

So,
x=38
y=29

5 0

4 years ago

<img src="https://tex.z-dn.net/?f=%20%5Csqrt%7B5%7D%20" id="TexFormula1" title=" \sqrt{5} " alt=" \sqrt{5} " align="absmiddle" c

WITCHER [35]

Answer:

2.2360679775

Step-by-step explanation:

6 0

4 years ago

Read 2 more answers

Which system is equivalent to 3x^2 - 4y^2 = 25

Archy [21]