PLEASE RIGHT ANSWERS ONLY!!

Given a mean of 150 and a standard deviation of 25:

pishuonlain [190]

We have to define an interval about the mean that contains 75% of the values. This means half of the values will lie above the mean and half of the values lie below the mean.

So, 37.5% of the values will lie above the mean and 37.5% of the values lie below the mean.

In a Z-table, mean is located at the center of the data. So the position of the mean is at 50% of the data. So the position of point 37.5% above the mean will be located at 50 + 37.5 = 87.5% of the overall data

Similarly position of the point 37.5% below the mean will be located at
50 - 37.5% = 12.5% of the overall data

From the z table, we can find the z value for both these points. 12.5% converted to z score is -1.15 and 87.5% converted to z score is 1.15.

Using these z scores, we can find the values which contain 75% of the values about the mean.

z score of -1.15 means 1.15 standard deviations below the mean. So this value comes out to be:

150 - 1.15(25) = 121.25

z score of 1.15 means 1.15 standard deviations above the mean. So this value comes out to be:

150 + 1.15(25) = 178.75

So, the interval from 121.25 to 178.75 contains the 75% of the data values.

4 0

3 years ago

Drew drives his car and Rachel drives her truck in the same direction on the highway at constant speeds for 3.25 hours. During t

never [62]

Answer:

After 4.5 hours of driving at the same constant speeds, Drew and Rachel are 6.5 miles apart.

Hope This Helps :)

4 0

3 years ago

7. All of the following are perfect square trinomials EXCEPT one. Which is it?

wolverine [178]

Answer:

All answers EXCEPT answer C. are perfect square trinomials.

Step-by-step explanation:

A perfect square trinomial is polynomial that satisfies the following condition:

$(a+b)^{2} = a^{2}+2\cdot a \cdot b + b^{2}$ , $\forall\,a,b\in\mathbb{R}$

Let prove if each option observe this:

a) $4\cdot x^{2} + 12\cdot x\cdot y + 9\cdot y^{2}$

1) $4\cdot x^{2} + 12\cdot x\cdot y + 9\cdot y^{2}$ Given

2) $(2\cdot x)^{2}+ 2\cdot (2\cdot x)\cdot (3\cdot y)+(3\cdot y)^{2}$ Definition of power/Distributive, associative and commutative properties.

3) $a = 2\cdot x$ , $b = 3\cdot y$ Definition of perfect square trinomial/Result.

b) $9\cdot a^{2}-36\cdot a + 36$

1) $9\cdot a^{2}-36\cdot a + 36$ Given.

2) $(3\cdot a)^{2}-2\cdot (3\cdot a)\cdot 6 + 6^{2}$ Definition of power/Distributive, associative and commutative properties.

3) $a = 3\cdot a$ , $b = 6$ Definition of perfect square trinomial/Result.

c) $x\cdot y^{2}-4\cdot x^{2}\cdot y^{2}+4\cdot x^{2}\cdot y^{2}$

1) $x\cdot y^{2}-4\cdot x^{2}\cdot y^{2}+4\cdot x^{2}\cdot y^{2}$ Given

2) $x\cdot y\cdot (1-4\cdot x+4\cdot x)$ Distributive property.

3) $x\cdot y \cdot 1$ Existence of the additive inverse/Modulative property.

4) $x\cdot y$ Modulative property/Result.

d) $a^{2}\cdot b^{2}+4\cdot a^{3}\cdot b + 4\cdot a^{4}$

1) $a^{2}\cdot b^{2}+4\cdot a^{3}\cdot b + 4\cdot a^{4}$ Given

2) $(a\cdot b)^{2}+2\cdot (a\cdot b)\cdot (2\cdot a^{2})+(2\cdot a^{2})$ Definition of power/Distributive, associative and commutative properties.

3) $a = a\cdot b$ , $b = 2\cdot a^{2}$ Definition of perfect square trinomial.

All answers EXCEPT answer C. are perfect square trinomials.

8 0

3 years ago

Samira buys a car the car loses 23% of its value in the first year. at the end of the first year her car is worth 6575.80 dollar

Andreyy89

Answer: Samira paid $8540 for her car.

Step-by-step explanation:

Let x = Amount paid by Samira for her car.

Given: Depreciation rate = 23%

Worth of car after one year = $ 6575.80

As per given,

x - 23 % of x = 6575.80

⇒ x - 0.23x = 6575.80

⇒ 0.77x= 6575.80

⇒ x= $8540 [Divide both sides by 0.77]

Hence, Samira paid $8540 for her car.

6 0

3 years ago

Please help. I don't get this.

vredina [299]

Answer:

5.5

Step-by-step explanation:

1+1+1 3/4+1 3/4= 5.5

5.5*2=11

11/2=5.5

5 0

3 years ago