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3 years ago

8

The talk-time battery life of a group of cell phone is normally distributed with a mean of 5 hours and a standard deviation of 1

5 minutes. A) What percent of the phones have a battery life of at least 4 hours and 45 minutes?

1 answer:

kiruha [24]3 years ago

6 0

The correct answer is 84%

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5-2.1=? 5-2.17=? 5-2 7/8 solve make sure to re-check your self before answering or no forty points

frozen [14]

Answer: 5-2.1= 2.9

5-2.17= 2.83

5-2 7/8= 2.125

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3 years ago

this graph shows the relationship between the pound of cheese brought at a deli and the total cost in dollars for the cheese

Savatey [412]

Easy! The best answer is B!

PLEASE GIVE ME THE BRAINLIEST I TRIED REALLY HARD ON THIS QUESITON!

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3 years ago

Kendra dives off a diving board into the water and then comes back up to the surface. Her dive can be modeled by the equation: ,

MAVERICK [17]

Answer:

1. 6 feet

2. 6.25 feet

3. 1 feet

4. 6 feet

Step-by-step explanation:

The equation is : $h(x)=x^2-7x+6$

1. The diving board is where Kendra dives off. Here, the horizontal distance, x from the diving board is 0.

So, substituting x = 0 in the equation, we get

$h(0)=0^2-7(0)+6$

$=0-0+6$

$=6$

So, the diving board is 6 feet above the surface of the water.

2. From the equation, we known that it is a parabola and the vertex is minimum.

It is the minimum height which represents the depth Kendra dives into the water.

So the $x$ coordinate of the vertex is = $\frac{-b}{2a}$

Here, a and b are the coefficients of linear term and the quadratic terms in the equation. Therefore,

a = 1 and b = -7

∴ x coordinate = $\frac{-(-7)}{2 \times 1}$

$\frac{7}{2}=3.5$

Now substituting to find f(x),

$h(3.5)=(3.5)^2-7(3.5)+6$

= -6.25

Therefore, the diver dives 6.25 feet below the water surface.

3. The horizontal distance from the board the diver enters into the water.

This is the y-intercept and it is the value of x when h(x)=0.

∴ $0=x^2-7x+6$

Factorizing, we get $(x-1)(x-6)=0$

∴ $x=1 \text{ or}\ x=6$

So there are two solutions that are the two x intercepts of the function. Here at x = 1 shows the horizontal distance from the board from where Kendra dives into the water.

4. We know that the equation given has $\text{two}$ x intercepts. These two x intercepts are the points where the parabola crosses the x-axis, which is the height $h(x)=0$ . The height is the water surface level.

The first x intercept represents the points where Kendra dives into the water.

And the second x intercept is the point where Kendra comes out of the water surface. This this is $x=6$ for $h(x)=0$ .

Thus Kendra dives out of the water surface at 6 feet from the board.

3 0

2 years ago

I need help finding the range and domain, you can use the images I've included for guidance! I need this asap thank youu

SCORPION-xisa [38]

Answer:

$\displaystyle Range: \\ Set-Builder\:Notation → y|1 ≥ y ≥ -1 \\ Interval\:Notation → [-1, 1] \\ \\ Domain: \\ Set-Builder\:Notation → x|x ∈ R \\ Interval\:Notation → (-∞, ∞)$

Step-by-step explanation:

This is the graph of $\displaystyle y = cos\:x,$ in which its AMPLITUDE [<em>A</em>] ALWAYS starts ONE BLOCK ABOVE the <em>midline</em><em>.</em><em> </em>In the trigonometric formula below, −C gives the OPPOSITE terms of what they really are, so be EXTREMELY CAREFUL:

$\displaystyle y = Acos[Bx - C] + D$

NOTE: Depending on how your trigonometric graphs are structured, your vertical shift [<em>D</em>] might tell you to space out the amplitude of the graphs alot more evenly on both ends.

<u>Extended</u><u> </u><u>Information on</u><u> </u><u>Trigonometric</u><u> </u><u>Graphs</u>

$\displaystyle Vertical\:Shift = D \\ Phase\:Shift\:[Horizontal\:Shift] = \frac{C}{B} \\ Period = \frac{2}{B}π \\ Amplitude = |A|$

I am joyous to assist you anytime.

7 0

3 years ago

Does anyone know the answer. The picture is below

nignag [31]

I say c is it I think

7 0

2 years ago

Read 2 more answers