The sum of two numbers is 12, and their difference is 17. What are the numbers.

I need step by step explanation for this!

damaskus [11]

Answer:

61

Step-by-step explanation:

13 - 1 = 12
12 ÷ 2 = 6
Put 6 and 1 together: 61

Therefore, the number is 61

Let's check:

6 × 2 = 12
12 + 1 = 13

The sum of the two digits is 13, and we got that, so we are correct. The number is 61.

5 0

3 years ago

Read 2 more answers

If edging cost $2.32 per 12-inch stone, and you want a double layer of edging around your flower bed that is 6 yards by 1 yard.

aksik [14]

12 inches = 1foot
1yard = 3feet
6yards = 18feet
Rerange the question:
If edging cost $2.32 per 1foot stone, and you want a double layer of edging around your flower bed that is 18feet by 3feet. How much will edging you flower bed cost?
Perimter:
2(18+3)=42
And since you want to double it; double the perimeter too.
42(2)=84

2.32(84)=194.88

7 0

3 years ago

Read 2 more answers

Which of th following is a solid bounded by the set of all points at a given distance from a given point ?

aleksandrvk [35]

C.Sphere is your answer it is bound to all it's points

4 0

3 years ago

Wires manufactured for use in a computer system are specified to have resistances between 0.11 and 0.13 ohms. The actual measure

Marina CMI [18]

Answer:

a) $P(0.11$

And we can find this probability with this difference and with the normal standard table or excel:

$P(-1.11$

b) $P(0.11 < \bar X < 0.13)$

And we can use the z score defined by:

$z = \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And using the limits we got:

$z = \frac{0.11-0.12}{\frac{0.009}{\sqrt{4}}}= -2.22$

$z = \frac{0.13-0.12}{\frac{0.009}{\sqrt{4}}}= 2.22$

And we want to find this probability:

$P(-2.22< Z$

Step-by-step explanation:

Previous concepts

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".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Part a

Let X the random variable that represent the resitances of a population, and for this case we know the distribution for X is given by:

$X \sim N(0.12,0.009)$

Where $\mu=0.12$ and $\sigma=0.009$

We are interested on this probability

$P(0.11$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(0.11$

And we can find this probability with this difference and with the normal standard table or excel:

$P(-1.11$

Part b

We select a sample size of n =4. And since the distribution for X is normal then we know that the distribution for the sample mean $\bar X$ is given by: