Ask question

Ask question

All categories

3 years ago

15

Find the length of a line segment with endpoints of -9 and 7.

1 answer:

Ratling [72]3 years ago

8 0

Let L be the length

so L=Lfinal - Linitial = 7 +9=16
the answer is
<span>C.16</span>

You might be interested in

What is 85% of 17,000 dollars that is asked on your irs tax forms

elena55 [62]

Hello!

17,000 * 85% = 14,450

85% of $17,000 is $14,450.

3 0

3 years ago

The length of a rectangle is 7 more than the width the area is 744 square centimeters find length and width of rectangle

andrezito [222]

Answer:

$l=31\ cm\\\\w=24\ cm$

Step-by-step explanation:

The formula that is used to calculate the area of a rectangle is:

$A=lw$

Where "l" is the lenght and "w" is the width.

You know that the area of that rectangle is:

$A=744\ cm^2$

And, according to the exercise, its lenght is 7 more than its width; then:

$l=w+7$

Then, you can make the corresponding substitution into the formula $A=lw$ :

$744=(w+7)w$

Simplify:

$744=w^2+7w\\\\w^2+7w-744=0$

Factor the equation. Find two numbers whose sum is 7 and whose product is -744. These are 31 and -24.

Then, you get:

$(w-24)(w+31)=0\\\\w_1=24\\\\w_2=-31$

The width of the rectangle is the positive value:

$w=24\ cm$

Then, the lenght is:

$l=24+7\\\\l=31\ cm$

8 0

3 years ago

One canned juice drink is 25%orange juice; another is 10%orange juice. how many liters of each should be mixed together in or

sertanlavr [38]

   Qty    · % = Total
Drink 1:    x .25 = .25x
Drink 2:   15 - x .10 = .10(15 - x)
Mixture: 15 .21 = .25x + .10(15 - x)

   (15)(.21)   =    .25x + 1.5 - .10x
   3.15 =    .15x + 1.5
   1.65 = .15x
   11    = x

Drink 1 (25%) is 11 liters
Drink 2 (10%) is 15 - 11 = 4 liters

6 0

3 years ago

Solve the equation <br> 13(x + 1) + 2x = 2

Goryan [66]

13x + 13 + 2x = 2
15x + 13 = 2
15x = -11

4 0

3 years ago

Read 2 more answers

The amount of time required for an oil and filter change on an automobile is normally distributed with a mean of 45 minutes and

Firdavs [7]

Answer:

1a

$P(39 < X < 48 ) = 0.8767$

1b

95% of all sample means will fall between $40.1 < \mu < 49.9$

1c

$\= x = 41. 795$

2

$n = 25$

Step-by-step explanation:

From the question we are told that

The mean is $n = 45$

The population standard deviation is $\sigma = 10$

The sample size is n = 16

Generally the standard error of the mean is mathematically represented as

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

=> $\sigma_{x} = \frac{ 10 }{\sqrt{16 } }$

=> $\sigma_{x} = 2.5$

Generally the probability that the sample mean will be between 39 and 48 minutes is

$P(39 < X < 48 ) = P( \frac{ 39 - 45}{ 2.5} < \frac{X - \mu }{\sigma } < \frac{ 48 - 45}{ 2.5} )$

=> $P(39 < X < 48 ) = P(-2.4 < Z< 1.2 )$

=> $P(39 < X < 48 ) = P( Z< 1.2 ) - P(Z < -2.4)$

From the z table the area under the normal curve to the left corresponding to 1.2 and -2.4 is

=> $P( Z< 1.2 ) = 0.88493$

and

$P( Z< - 2.4 ) = 0.0081975$

So

$P(39 < X < 48 ) = 0.88493 -0.0081975$

=> $P(39 < X < 48 ) = 0.8767$

From the question we are told the confidence level is 95% , hence the level of significance is

$\alpha = (100 - 95 ) \%$

=> $\alpha = 0.05$

Generally from the normal distribution table the critical value of is

$Z_{\frac{\alpha }{2} } = 1.96$

Generally the margin of error is mathematically represented as

$E = Z_{\frac{\alpha }{2} } * \frac{\sigma }{\sqrt{n} }$

=> $E = 1.96 * 2.5$

=> $E =4.9$

Generally the 95% of all sample means will fall between

$\mu -E < and \mu +E$

=> $45 -4.9\ and \ 45 + 4.9$

Generally the value which 90% of sample means is greater than is mathematically represented

$P( \= X > \= x ) = 0.90$

=> $P( \= X > \= x ) = P( \frac{\= X - \mu }{ \sigma_x} > \frac{\= x -45 }{ 2.5} ) = 0.90$

=> $P( \= X > \= x ) = P( Z > z ) = 0.90$

Generally from the z-table the critical value of 0.90 is

$z = -1.282$

$\frac{\= x -45 }{ 2.5} = -1.282$

=> $\= x = 41. 795$

Considering question 2

Generally we are told that the standard deviation of the mean to be one fifth of the population standard deviation, this is mathematically represented as

$s = \frac{1}{5} \sigma$

Generally the standard deviation of the sample mean is mathematically represented as

$s = \frac{\sigma }{ \sqrt{n} }$

=> $\frac{1}{5} \sigma = \frac{\sigma }{ \sqrt{n} }$

=> $n = 5^2$

=> $n = 25$

5 0

3 years ago