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3 years ago

What is the value of x in 0.8x = 7.2

Mathematics

2 answers:

Gelneren [198K]3 years ago

5 0

Answer:

Step-by-step explanation:

7.2 ÷ 0.8 = 9

x = 9

Ann [662]3 years ago

4 0

Answer:

x = 9

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS
Equality Properties

Step-by-step explanation:

Step 1: Define equation

0.8x = 7.2

Step 2: Solve for x

Divide both sides by 0.8: x = 9

Step 3: Check

Plug in x to verify it's a solution.

Substitute: 0.8(9) = 7.2
Multiply: 7.2 = 7.2

7.2 does indeed equal 7.2. ∴ x = 9 is a solution.

And we have our final answer!

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After the booster club sold 40 hotdogs at a football game, it had $90 in profit. After the next game, it had sold a total of 80

Ainat [17]

We can model the equation:y = m x + b, where y is the total profit and x is the number of hotdogs sold.The system of equations is:
90 = 40 m + b210 = 80 m + b---------------------b = 90 - 40 m210 = 80 m + 90 - 40 m210 - 90 = 40 m120 = 40 mm = 120 : 40m = 3b = 90 - 40*3b = 90 - 120b = - 30Answer: The equation is y = 3 x - 30

5 0

3 years ago

Suppose you pick two cards from a deck of 52 playing cards. What is the probability that they are both queens?

photoshop1234 [79]

Answer:

0.45% probability that they are both queens.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes

The combinations formula is important in this problem:

$C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

Desired outcomes

You want 2 queens. Four cards are queens. I am going to call then A,B,C,D. A and B is the same outcome as B and A. That is, the order is not important, so this is why we use the combinations formula.

The number of desired outcomes is a combinations of 2 cards from a set of 4(queens). So

$D = C_{4,2} = \frac{4!}{2!(4-2)!} = 6$

Total outcomes

Combinations of 2 from a set of 52(number of playing cards). So

$T = C_{52,2} = \frac{52!}{2!(52-2)!} = 1326$

What is the probability that they are both queens?

$P = \frac{D}{T} = \frac{6}{1326} = 0.0045$

0.45% probability that they are both queens.

4 0

3 years ago

A small business owner estimates his mean daily profit as $970 with a standard deviation of $129. His shop is open 102 days a ye

Katena32 [7]

Answer:

The probability that the shopkeeper's annual profit will not exceed $100,000 is 0.2090.

Step-by-step explanation:

According to the Central Limit Theorem if we have a population with mean μ and standard deviation σ and we select appropriately huge random samples (n ≥ 30) from the population with replacement, then the distribution of the sum of values of X, i.e ∑X, will be approximately normally distributed.

Then, the mean of the distribution of the sum of values of X is given by,

$\mu_{x}=n\mu$

And the standard deviation of the distribution of the sum of values of X is given by,

$\sigma_{x}=\sqrt{n}\sigma$

The information provided is:

μ = $970

σ = $129

n = 102

Since the sample size is quite large, i.e. n = 102 > 30, the Central Limit Theorem can be used to approximate the distribution of the shopkeeper's annual profit.

Then,

$\sum X\sim N(\mu_{x}=98940,\ \sigma_{x}=1302.84)$