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2 years ago

A set of physics exam scores are normally distributed with a mean of 80 points and a standard deviation of 6

Mathematics

1 answer:

Anuta_ua [19.1K]2 years ago

3 0

Answer:

The proportion of exam scores that are lower than Irina's score is 0.9938

Step-by-step explanation:

mean: 80 points

standard deviation (sd): 6 points
value of interest (x): 95 points

z-score is computed as follows:

z = (x - mean)/sd

z = (95 - 80)/6 = 2.5

We want to find:

P(z < 2.5)

From the table attached:

P(z < 2.5) = 0.9938

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Help me please and thank you

sdas [7]

Answer:

Based on the model, the length of the wall is $\frac{9}{8}$ ft, the width of the wall is $\frac{1}{2}$ ft, and the height of the wall is $\frac{11}{8}$ ft. The volume of the portion of security wall that Tim has constructed so far is $\frac{99}{128}$ cu ft.

Step-by-step explanation:

Given:

The figure constructed shows a rectangular prism made up of small wooden cubes of length $\frac{1}{8}\ ft$ .

Width of the prism = $\frac{1}{2}\ ft$ .

To find length , height and volume of the figure.

Solution:

From the figure we can conclude that :

Length side of the prism counts 9 cubes.

Thus, length of the prism will be given as :

⇒ $\textrm{Length of each cube}\times \textrm{Number of cubes}$

⇒ $\frac{1}{8}\ ft\times 9$

⇒ $\frac{9}{8}\ ft$ (Answer)

Height side of the prism counts 11 cubes.

Thus, height of the prism will be given as :

⇒ $\textrm{Length of each cube}\times \textrm{Number of cubes}$

⇒ $\frac{1}{8}\ ft\times 11$

⇒ $\frac{11}{8}\ ft$ (Answer)

Volume of the prism can be given as :

⇒ $Length\times width\times height$

⇒ $\frac{9}{8}\ ft\times \frac{1}{2}\ ft\times \frac{11}{8}\ ft$

⇒ $\frac{99}{128}\ ft^3$ (Answer)

7 0

2 years ago

Ann has 30% less money than Mary, and Jessica has 70% more than Mary. If the 3 of them have a (added up) total of $102, how much

Roman55 [17]

Let x be the amount of Ann money, y be Jessica's money and z Mary money.
30% of z equates 0.3*z.
Ann has 30% less than z so: x = z - 0.3z = 0.7z.
70% of z equates 0.7z.
"Jessica has 70% more than Mary " we deduce the equation: y =z+0.7z= 1.7z.
Signe the total is $102, we deduce the equation x+y+z = 102.
x=0.7z and y=1.7z then 0.7z+1.7z+z=102, therefore 3.4z=102 then
z =102/3.4 = $30.
x=0.7*30= 21 and y=1.7*30=51.

Ann has $21, Mary has $30 and Jessica has $51.

3 0

3 years ago

E^3x.cos4x.sin2x hii please solv this you have to differentiate

finlep [7]

Answer:

$y = e^{3x}.cos4x.sin2x$

$=> y' =- 3e^{3x}.4sin4x.2cos2x=-24.e^{3x}.sin4x.cos2x$

$dy=y'.dx => dy = -24e^{3x}.sin4x.cos2x.dx$

Step-by-step explanation:

6 0

2 years ago

John is painting parallel lines in the parking lot to create parking spaces. The measure of angle A is 60°. What is the measure

ohaa [14]

If you're on Plato, the answer is 60.

8 0

3 years ago

The area of a rectangle is expressed as (14x + 28) square feet. If the width of the rectangle is 7 feet, write an expression to

DochEvi [55]

Answer:

The expression for the length of the rectangle is 2x + 4

Step-by-step explanation:

The formula for determining the area of a rectangle is expressed as

Area = length × width

The area of a rectangle is expressed as (14x + 28) square feet. If the width of the rectangle is 7 feet, then the expression for the length of the rectangle would be

Length = Area/ width

= (14x + 28)/7

The numerator has a common factor of 7. Therefore, if we factorize 7 out, it becomes

7(2x + 4)/7

Length = 2x + 4

7 0

2 years ago