What is x more than 3x-1

Which expression is equivalent to 2(3 - x) - 12 + 4x

iragen [17]

You would distribute then combine like terms to get your answer.

3 0

3 years ago

Uma rede de supermercados fornece a seus clientes um cartão de crédito cuja identificação é formada por 3 letras distintas (dent

Vitek1552 [10]

Answer:

The correct option is (A) 33,600.

Step-by-step explanation:

The question is:

A supermarket chain provides its customers with a credit card whose identification is formed by 3 different letters (among 26), followed by 4 different digits. A given city will receive cards with L as the third letter, the last number is zero and the penultimate is 1. The total number of distinct cards offered by such supermarket chain for that city is A) 33600 B) 37800 C) 43200 D ) 58500 E) 67600

Solution:

The general format of the credit cards provided by a supermarket chain is as follows:

X X X # # # #

Here, X represents letters and # represents numbers.

All the three letters have to different and all the four numbers have to different, i.e. no repetition allowed.

It is provided that a given city will receive cards with L as the third letter, the last number is zero and the penultimate is 1.

Then the general format of this cities credit cards is as follows:

X X L # # 1 0

Now there are two spaces left for letters and 2 for numbers.

As there are no repetition allowed the two letter spaces can be filled by:

Number of ways to select 2 letters = 25 × 24 = 600

And the number of ways to select two numbers when there is no repetition allowed is:

Number of ways to select 2 numbers = 8 × 7 = 56

Compute the total number credit cards available at the supermarket as follows:

Total number credit cards = 600 × 56 = 33600

Thus, the total number of distinct cards offered by such supermarket chain for that city is 33,600.

The correct option is (A).

3 0

3 years ago

Please give me a real answer or I will report you I dont want to friend you just put the answers in the comments

kotykmax [81]

Answer:

j = 17.32 sq rt 3 or 30

Step-by-step explanation:

sin 60 = j/20sq rt 3

0.8660 = j/20sq rt 3

j = 17.32 sq rt 3

4 0

3 years ago

) The National Assessment of Educational Progress (NAEP) gave a test of basic arithmetic and the ability to apply it in everyday

Vsevolod [243]

Answer:

a) The standard deviation of this sampling distribution is 2.07.

b) The missing number is 4.14.

c) The 95% confidence interval for the population mean score μ based on this one sample is between 267.86 and 276.14.

Step-by-step explanation:

To solve this question, we need to understand the Empirical Rule and the Central Limit Theorem.

Empirical Rule:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

Central Limit Theorem:

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this question:

$\mu = 272, n = 840, \sigma = 60$

(a) If we take many samples, the sample mean x⎯⎯⎯ varies from sample to sample according to a Normal distribution with mean equal to the unknown mean score μ in the population. What is the standard deviation of this sampling distribution?

Using the Central Limit Theorem:

$s = \frac{\sigma}{\sqrt{n}} = \frac{60}{\sqrt{840}} = 2.07$

The standard deviation of this sampling distribution is 2.07.

(b) According to the 95 part of the 68-95-99.7 rule, 95% of all values of x⎯⎯⎯ fall within _______ on either side of the unknown mean μ. What is the missing number?

Within 2 standard deviations of the mean.

So, 2*2.07 = 4.14

The missing number is 4.14.

(c) What is the 95% confidence interval for the population mean score μ based on this one sample?

Within 4.14 of the mean

272 - 4.14 = 267.86

272 + 4.14 = 276.14

The 95% confidence interval for the population mean score μ based on this one sample is between 267.86 and 276.14.

6 0

3 years ago

A store is giving away a $10 dollar coupon to every 7th person to enter the store and a $25 coupon to every 18th person to enter

muminat

A store is giving away a $10 dollar coupon to every 7th person to enter the store and a $25 coupon to every 18th person to enter the store.

To find the first person to get both coupons, you have to find the LCM of 7 and 18. First list the multiples of each number.

7 - 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105, 112, 119, 126, 133

18 - 18, 36, 54, 72, 90, 108, 126, 144

The common multiples are bold. The 126th person will be the first to get both coupons.

7 0

3 years ago