This whole page is going to be 30 points!!!!!

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 $t_{\alpha/2}=4.604$

Now we have everything in order to replace into formula (1):

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

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

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

6 0

3 years ago

Pythagorean triples are super important to know. If the hypotenuse of a triangle is 15, what are its legs ( hint - use the three

Triss [41]

Answer:

9, 12

Step-by-step explanation:

Just multiply the 3,4,5 triple by 3 and u get 9, 12, 15

8 0

3 years ago

If a 750 ml bottle of juice costs £1.90 and a 1 litre bottle of the same juice costs £2.50 then the 750 ml bottle is better valu

frozen [14]

Answer:

The 1 liter bottle is better value

Step-by-step explanation:

Cost of 750 ml = £1.90

Cost of 1 liter = £2.50

1000 ml = 1 liter

Cost per 250 ml

750 ml / 3 = £1.90 / 3

250 ml = £0.6333333333333

Approximately,

£ 0.633

Cost per 250 ml

1 liter / 4 = £2.50 / 4

250 ml = £0.625

The 750 ml bottle is not a better value

The 1 liter bottle is better value

5 0

3 years ago

I need help with this I don’t know how many terms there are.

Alekssandra [29.7K]

A:

So terms are a group of numbers/variables or a single number/variable. They are separated by + and - symbols.

In the original equation, there are 6 terms: 5x^2, 6x, -3, 4x^2, -8x, and 2.

To find the simplified equation, just combine like terms, which in this case are (5x^2 + 4x^2) + (6x - 8x) + (-3 + 2).

Simplify that, and your simplified equation is 9x^2 - 2x - 1 . And within this simplified equation, there are 3 terms: 9x^2, -2x, and -1.

B:

Going back to A, we see that our simplified expression is 9x^2 - 2x - 1 . Looking at our equation, the coefficient of x is -2.

3 0

3 years ago

Please answer ASAP! An explanation is a MUST REQUIREMENT in order to receive points and the Brainliest answer. Thank you.

Advocard [28]

Hmm

tr some
m=3
n=4
p=5
q=6
A=m/q=3/6=1/2=0.5
B=n/p=4/5=0.8

test
first,
A+B, andB is irrational
hmm, B is not irrational and the result is not irrational

2nd
0.5+0.8=1.3, it is rational

3rd the fraction is wrong
m/q times n/p=(mn)/(qp) so this is wrong

4th, fraction is also wrong (but it is true that produce of 2 rationals makes rational)

pick 2nd from top

7 0

3 years ago