What would the exponent be when 9540000 is written in scientific notation?

My teacher makes us read the book to learn and the book doesnt show how to solve something like this

Gre4nikov [31]

If the mean score is 55% and the s.d. is 15%, then a test score of at least

55% + 1.5 × 15% = 77.5%

falls in the A range.

The next cutoff score is 0.5 s.d. from the mean, which is

55% + 0.5 × 15% = 62.5%

so any test score between 62.5% and 77.5% is in the B range.

The next cutoff is

55% - 0.5 × 15% = 47.5%

so a score between 47.5% and 62.5% gets a C.

The lower limit of the next range is

55% - 1.5 × 15% = 32.5%

so 32.5% - 47.5% gets a D.

Anything lower than 32.5% is an F.

7 0

2 years ago

Two points on a line are (4,-1) and (1,5) what is the slope of the line

ser-zykov [4K]

Answer: -2

I hope this helps and may God bless you! Have a nice day, bye! :)

4 0

2 years ago

Tina's aquarium has a capacity of 40 gallons or water. She plans to stock her aquarium with 0.25 inches of fish per quart of cap

Sonbull [250]

Answer:

The number of mollies fishes in the aquarium is 20 .

Step-by-step explanation:

Given as :

The capacity of aquarium = 40 gallons

∵ 1 gallon = 4 quart

∴ 40 gallons = 4 × 40 = 160 quart

Now, According to question

0.25 inches of fish required 1 quart capacity

I.e for 1 quart capacity , 0.25 inches fish

So. for 160 quart capacity , 0.25 × 160 = 40 inches fishes

Now the size of mollies fish = 2 inches

Then , number of mollies fish = $\dfrac{\textrm total size of fishes}{\textrm size of mollies fish}$

I.e Number of mollies fish = $\frac{40}{2}$ = 20

Hence The number of mollies fishes in the aquarium is 20 . Answer

3 0

2 years ago

Write the equation of the line perpendicular to 2x+3y=9 that passes through (-2,5). Write your answer in slope-intercept form. S

Harman [31]

ANSWER

$y = \frac{3}{2} x + 8$

EXPLANATION

The line given to us has equation,

$2x + 3y = 9$

We need to write this equation in the slope intercept form to obtain,

$3y = - 2x + 9$

$\Rightarrow \: y = - \frac{2}{3}x + 3$

The slope of this line is

$m_1 = - \frac{2}{3}$
Let the slope of the perpendicular line be

$m_2$

Then
$m_1 \times m_2 = - 1$

$- \frac{2}{3} m_2= - 1$

This implies that,

$m_2 = - 1 \times - \frac{3}{2}$

$m_2 = \frac{3}{2}$

Let the equation of the perpendicular line be,

$y = mx + b$

We substitute the slope to get,

$y = \frac{3}{2} x + b$

Since this line passes through
$(-2,5)$
it must satisfy its equation.

This means that,

$5= \frac{3}{2} ( - 2)+ b$

$5 = - 3 + b$

$5 + 3 = b$

$b = 8$

Wherefore the slope-intercept form is

$y = \frac{3}{2} x + 8$

6 0

3 years ago

A firework is launched at the rate of 10 feet per second from a point on the ground 50 feet from an observer. to 2 decimal place

Kazeer [188]

The rate of change of the angle of elevation when the firework is 40 feet above the ground is 0.12 radians/second.

First we will draw a right angle triangle ΔABC, where ∠B = 90°

Lets, assume the height(AB) = h and base(BC)= x

If the angle of elevation, ∠ACB = α, then

tan(α) = $\frac{AB}{BC} = \frac{h}{x}$

Taking inverse trigonometric function, α = tan⁻¹ ( $\frac{h}{x}$ ) .............(1)

As we need to find the rate of change of the angle of elevation, so we will differentiate both sides of equation (1) with respect to time (t) :

$\frac{d\alpha}{dt}=[\frac{1}{1+ \frac{h^2}{x^2}}]*(\frac{1}{x})\frac{dh}{dt}$

Here, the firework is launched from point B at the rate of 10 feet/second and when it is 40 feet above the ground it reaches point A,

that means h = 40 feet and $\frac{dh}{dt}$ = 10 feet/second.

C is the observer's position which is 50 feet away from the point B, so x = 50 feet.

$\frac{d\alpha}{dt}= [\frac{1}{1+ \frac{40^2}{50^2}}] *\frac{1}{50} *10\\ \\ \frac{d\alpha}{dt} = [\frac{1}{1+\frac{16}{25}}] *\frac{1}{5}\\ \\ \frac{d\alpha}{dt} = [\frac{25}{41}] *\frac{1}{5}\\ \\ \frac{d\alpha}{dt}= \frac{5}{41} =0.1219512$

= 0.12 (Rounding up to two decimal places)

So, the rate of change of the angle of elevation is 0.12 radians/second.

5 0

3 years ago