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alukav5142 [94]

2 years ago

6

What is a solution to (x 6)(x 2) = 60? x = −6 x = −4 x = 4 x = 12

2 answers:

Kryger [21]2 years ago

6 0

(x+6)(x+2)=60
expand
x^2+6x+2x+12=60
x^2+8x+12=60
minus 60 both sides
x^2+8x-48=0
factor
what multiplies to -48 and adds to 8
-4 and 12
(x-4)(x+12)=0
set each to zero

x-4=0
x=4

x+12=0
x=-12

x=4 or -12

solutions are x=-12 and 4

Lesechka [4]2 years ago

5 0

Answer:

Its C

Step-by-step explanation:I got it right

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in a random sample of 200 people, 154 said that they watched educational television. fine the 90% confidence interval of the tru

melisa1 [442]

Answer:

[0.7210,0.8189] = [72.10%, 81.89%]

Step-by-step explanation:

The sample size is

n = 200

the proportion is

p = 154/200 = 0.77

<em>Since both np ≥ 10 and n(1-p) ≥ 10 </em>

<em>We can approximate this discrete binomial distribution with the continuous Normal distribution. As the sample size is large enough, not applying the continuity correction factor makes no significant difference. </em>

The approximation would be to a Normal curve with this parameters:

<em>Mean </em>

p = 0.77

<em>Standard deviation </em>

$\bf s=\sqrt{\frac{p(1-p)}{n}}=\sqrt{\frac{0.77*0.23}{200}}=0.0298$

The 90% confidence interval for the proportion would be then

$\bf [0.77-z^*0.0298, 0.77+z^*0.0298]$

where $\bf z^*$ is the 10% critical value for the Normal N(0,1) distribution , this is a value such that the area under the N(0,1) curve outside the interval $\bf [-z^*,z^*]$ is 10%=0.1

We can either use a table, a calculator or a spreadsheet to get this value.

In Excel or OpenOffice Calc we use the function

<em>NORMSINV(0.95) and we get a value of 1.645 </em>

The 90% confidence interval for the proportion is then

$\bf [0.77-1.645^*0.0298, 0.77+1.645^*0.0298]=[0.7210,0.8189]$

This means there is a 90% probability that the proportion of people who watch educational television is between 72.10% and 81.89%

If the television company wanted to publicize the proportion of viewers, do you think it should use the 90% confidence interval?

Yes, I do.

5 0

2 years ago

On a coordinate plane, a triangle has points A prime (negative 2, 10), B prime (negative 6, 4), and (negative 10, 8). What is th

schepotkina [342]

Answer:

A(10,-2).

Step-by-step explanation:

It is given that, on a coordinate plane, a triangle has points A'(-2, 10), B'(-6, 4), and C'(-10, 8).

We need to find the pre-image of vertex A' if the image shown on the graph was created by a reflection across the line y = x.

If a figure reflected across the line y=x, then

$A(x,y)\rightarrow A'(y,x)$

It is given that A'(-2,10).

$A(y,x)=A'(-2,10)$

On comparing both sides, we get

$x=10,y=-2$

Therefore, the coordinates of preimage of A' are (10,-2).

8 0

1 year ago

When comparing functions, such as Seth’s scenarios for travelling to school, will the function with the greatest initial value c

True [87]

Answer:

It will depend whether is function time dependent or not.

Step-by-step explanation:

If the function is time dependent, the function with greatest initial values continue to be greatest as time increases.

4 0

2 years ago

Read 2 more answers

The scale is 0.25 cm: 15 km. FInd the actual distance corresponding to each map distance.

sweet-ann [11.9K]

If 0.25cm = 15 km the answer would divide 0.75 by0.25=3
next multiply 3 by 15km to get 45km

8 0

2 years ago

Write a power that has a value greater than 340 and less 345

valina [46]

For this case we must write a power between (340,345)

We chose 343.

We divide the number until we get an exact division:

$\frac {343} {2} = 171.5\\\frac {343} {3} = 114.3\\\frac {343} {4} = 85.75\\\frac {343} {5} = 68.6\\\frac {343} {6} = 57.17\\\frac {343} {7} = 49\\$

So we have:

$7 ^ n = 343\\n = 3$

So, the power is:

$7 ^ 3 = 7 * 7 * 7 = 49 * 3 = 343$

ANswer:

$7 ^ 3 = 7 * 7 * 7 = 49 * 3 = 343$

6 0

2 years ago

Read 2 more answers