Perform the operation and simplify 3x^2/x^2-x-30-3x+5/x-6

A random sample of 85 sixth-graders in a large city take a course designed to improve scores on a reading comprehension test. Ba

BartSMP [9]

Answer:

$12.6 < \mu < 14.8$

For this case we can find the margin of error like this:

$ME= \frac{14.8-12.6}{2}= 1.1$

Since we need to divide the width of the interval by 2.

And now with the margin of error we can find the sample mean with any of the two following ways:

$12.6 +1.1=13.7$

$14.8-1.1=13.7$

So for this case the correct answer would be:

A. Sample Mean = 13.7; Margin of Error = 1.1

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".

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

$df=n-1=85-1=84$

We know that the confidence interval is given by:

$12.6 < \mu < 14.8$

For this case we can find the margin of error like this:

$ME= \frac{14.8-12.6}{2}= 1.1$

Since we need to divide the width of the interval by 2.

And now with the margin of error we can find the sample mean with any of the two following ways:

$12.6 +1.1=13.7$

$14.8-1.1=13.7$

So for this case the correct answer would be:

A. Sample Mean = 13.7; Margin of Error = 1.1

3 0

3 years ago

550 tickets were sold for a game for a total of $712.50. If adult tickets sold for $1.50 and children's tickets sold for $1.00,

EastWind [94]

9514 1404 393

Answer:

adult: 325
children's: 225

Step-by-step explanation:

It usually works well to let a variable represent the higher-value item in the mix. Here, we can let 'a' represent the number of adult tickets sold. Then the total revenue is ...

1.50a +1.00(550 -a) = 712.50

0.50a = 162.50 . . . . . . . . . . . . . subtract 550 and collect terms

a = 325

c = 550 -325 = 225

325 adult and 225 children's tickets were sold.

4 0

3 years ago

a shopper paid $52 for a handbag during a sale. The handbag was priced at 65% off its original price. Which equation can be used

aleksklad [387]

52 ×.65= X The answer would be $80. Hope i could be helpful :)

8 0

3 years ago

What’s the equation.?

Stella [2.4K]

Answer:

See below

Step-by-step explanation:

You know that he spent 1/3 of his earnings, and then 1/4. After this, he has $28.90. You can write the equation like this:

1/4(x * 1/3) = $28.90.

If you need to solve it:

1/4 * 1/3x = 28.90

1/12x = 28.90

x = 346.80

8 0

3 years ago

By paying $1500 cash and the balance is equal monthly payments, how many months would it take to pay for a car costing $12,495?

Elden [556K]

The monthly installments need to be paid is $10995.

To determine the number of months needed to pay off the remaining balance. We need to know the monthly installment.

<h3>What is installments?</h3>

When you get an installment loan, you get the money you borrowed or the item you bought right away.

You pay it off in installments, which are regularly scheduled payments that may include interest.
For a set number of months, or years, you generally owe the same amount on every installment.
When the loan is fully repaid, the account is permanently closed.

Now, as per the question;

Amount paid in cash = $1500

Remaining balance which is to be paid as monthly installments

= $12495 - $1500

=$12495 − $1500

=$10995

Thus, the monthly installments are $10995.

Now, to determine the number of months needed to pay off the remaining balance. The monthly installment is need to be known.

As a result, information on monthly installments is lacking.

To know more about the installments, here

brainly.com/question/16032019

#SPJ4

The complete question is-

What necessary piece of information is missing that prevents solving the problem? By paying $1500 cash and the balance in equal monthly payments, how many months would it take to pay for a car costing$12,495?

4 0

2 years ago