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3 years ago

Which expression is equivalent to the following expression 3+13+3+13+3+13 : a) 3(13) b) 3(3+13) c)3×13 d) 3(3×13)

Mathematics

1 answer:

Alex Ar [27]3 years ago

8 0

Answer:

The answer is B

Step-by-step explanation:

3+3+3+13+13+13

This is 3 times 3

This is also 3 times 13

Which would be 3(3+13)

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Fofino [41]

Answer:

. We assume, that the number 260 is 100% - because it's the output value of the task.

2. We assume, that x is the value we are looking for.

3. If 260 is 100%, so we can write it down as 260=100%.

4. We know, that x is 6.75% of the output value, so we can write it down as x=6.75%.

5. Now we have two simple equations:

1) 260=100%

2) x=6.75%

where left sides of both of them have the same units, and both right sides have the same units, so we can do something like that:

260/x=100%/6.75%

6. Now we just have to solve the simple equation, and we will get the solution we are looking for.

7. Solution for what is 6.75% of 260

260/x=100/6.75

(260/x)*x=(100/6.75)*x - we multiply both sides of the equation by x

260=14.814814814815*x - we divide both sides of the equation by (14.814814814815) to get x

260/14.814814814815=x

17.55=x

x=17.55

now we have:

6.75% of 260=17.55

Step-by-step explanation:

5 0

3 years ago

What is 1+1? Wrong answers only

pishuonlain [190]

Answer:

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

Lee needed to make full length curtains to fit from the top of the window to the floor. The wall beneath the window had the heig

worty [1.4K]

Add the 2 together
2 2/3 + 2 3/4 you need a common denominator to add fractions
2 8/12 + 2 9/12 = 4 17/12 =
5 5!12 feer

7 0

3 years ago

A population has a mean of 200 and a standard deviation of 50. Suppose a sample of size 100 is selected and x is used to estimat

AveGali [126]

Answer:

a) 68% probability that the sample mean will be within ±5 of the population mean.

b) 95% probability that the sample mean will be within ±10 of the population mean.

Step-by-step explanation:

To solve this problem, we have 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 random variable X, with mean $\mu$ and standard deviation $\sigma$ , a large sample size can be approximated to a normal distribution with mean $\mu$ and standard deviation $s= \frac{\sigma}{\sqrt{n}}$

In this problem, we have that:

Mean: $\mu = 200$

Standard deviation of the population: $\sigma = 50$

Size of the sample: $n = 100$

Standard deviation for the sample mean: $s = \frac{50}{\sqrt{100}} = 5$

a.What is the probability that the sample mean will be within ±5 of the population mean?

5 is one standard deviation from the mean.

By the Empirical Rule, 68% probability that the sample mean will be within ±5 of the population mean.

b.What is the probability that the sample mean will be within ±10 of the population mean?

10 is two standard deviations from the mean

By the Empirical Rule, 95% probability that the sample mean will be within ±10 of the population mean.

4 0

3 years ago

If sin 49° is approximately 3/4, which is closest to the length of the of NO ?

tiny-mole [99]

Answer:

75 meters.

Step-by-step explanation:

In this case, you are trying to find side length NO. In accordance to SOH CAH TOA, you can use a sine function to find the missing side length, since you are given the hypotenuse.

sin(49) = x / 100

x = sin(49) * 100

x = 0.7547095802 * 100

x = 75.47095802

So, the closest answer would be 75 meters.

Hope this helps!

6 0

3 years ago