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3 years ago

A number, n, is multiplied by -7/8. The product is -0.5. What is the value of n?

Mathematics

1 answer:

Yuki888 [10]3 years ago

3 0

Answer: A.n = 4/7

have:

$n.\frac{-7}{8} =-0.5\\\\n.\frac{-7}{8}=\frac{-1}{2}\\\\n=\frac{-1}{2}:\frac{-7}{8}=\frac{4}{7}$

Step-by-step explanation:

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Harper borrowed $6,200 from the bank. 1 year later, Harper owes the bank $6,696. What was the percentage rate of simple interest

Fofino [41]

The rate of simple interest for loan was 8%

Step-by-step explanation:

Given

Principal amount = p = $6200

Time = t = 1 year

Amount after interest = $6696

We have to calculate the amount of interest first

So,

Interest amount =I= Amount after interest - principal amount

= 6696-6200

=$496

The formula for simple interest is:

$I =prt\\Here\\r\ is\ rate\\p\ is\ principal amount\\t\ is\ timePutting\ the\ values\\496=6200*r*1\\r=\frac{496}{6200}\\r=0.08\\r=0.08*100\\r=8\%$

The rate of simple interest for loan was 8%

Keywords: Simple interest, percentage

Learn more about simple interest at:

#LearnwithBrainly

7 0

3 years ago

What is 13 - 4x = 1 - x

JulsSmile [24]

13-4x=1-x
13=4x+x=1-x+x
13-3x=1
13-1-3x=1-1
12-3x=0
12=3x
12/3=3x/3
4=x
Therefore, x=4

5 0

4 years ago

How many Solutions does 6 + x/5 = x/5 - 5 - 3x/10 have?

klasskru [66]

9514 1404 393

Answer:

1 solution (x = -36 2/3)

Step-by-step explanation:

6 + x/5 = x/5 - 5 - 3x/10 . . . . . . . given

60 +2x = 2x -50 -3x . . . . . . . . . multiply by 10

3x = -110 . . . . . . . . . . . . . . . . add x-60 to both sides

x = -110/3 = -36 2/3 . . . . . .divide by the coefficient of x

There is one solution to the equation.

_____

Additional comment

The coefficient of x on the left side of the equation is not equal to the coefficient of x on the right side. When that is the case, the equation will have one solution.

When the coefficients are equal, there will be no solutions if the constants are different, and there will be infinite solutions if the constants are the same.

6 0

3 years ago

A certain type of thread is manufactured with a mean tensile strength of 78.3 kilograms and a standard deviation of 5.6 kilogram

azamat

Answer:

(a) The variance decreases.

(b) The variance increases.

Step-by-step explanation:

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

Then, the mean of the sample mean is given by,

$\mu_{\bar x}=\mu$

And the standard deviation of the sample mean is given by,

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

The standard deviation of sample mean is inversely proportional to the sample size, n.

So, if n increases then the standard deviation will decrease and vice-versa.

(a)

The sample size is increased from 64 to 196.

As mentioned above, if the sample size is increased then the standard deviation will decrease.

So, on increasing the value of n from 64 to 196, the standard deviation of the sample mean will decrease.

The standard deviation of the sample mean for n = 64 is:

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}=\frac{5.6}{\sqrt{64}}=0.7$

The standard deviation of the sample mean for n = 196 is:

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}=\frac{5.6}{\sqrt{196}}=0.4$

The standard deviation of the sample mean decreased from 0.7 to 0.4 when n is increased from 64 to 196.

Hence, the variance also decreases.

(b)

If the sample size is decreased then the standard deviation will increase.

So, on decreasing the value of n from 784 to 49, the standard deviation of the sample mean will increase.

The standard deviation of the sample mean for n = 784 is:

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}=\frac{5.6}{\sqrt{784}}=0.2$

The standard deviation of the sample mean for n = 49 is:

$\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}=\frac{5.6}{\sqrt{49}}=0.8$

The standard deviation of the sample mean increased from 0.2 to 0.8 when n is decreased from 784 to 49.

Hence, the variance also increases.

6 0

3 years ago

A builder was building a fence. In the morning, he worked for 25 of an hour. In the afternoon, he worked for 910 of an hour. How

Furkat [3]

9514 1404 393

Answer:

(9/10)/(2/5) = ratio of work times

2 1/4 times as long

Step-by-step explanation:

Given:

2/5 hours work in the morning

9/10 hours work in the afternoon

Find:

an equation for how many times as long was afternoon work compared to morning work

the equation solution

Solution:

a/m = r . . . . ratio of afternoon work to morning work

(9/10)/(2/5) = r . . . equation

(9/10)/(4/10) = r

9/4 = r = 2 1/4 . . . solution

The builder worked 2 1/4 times as long in the afternoon as in the morning.

8 0

3 years ago