A, B, C, D, or E????

Suppose the scores on a test given to all juniors in a school district are normally distributed with a mean of 74 and a standard

ivann1987 [24]

Answer:

$\mu -\sigma = 66 , \mu +\sigma = 82$

$\mu -2\sigma = 58 , \mu +2\sigma = 90$

$\mu -3\sigma = 50 , \mu +3\sigma = 98$

And in the figure attached we see the limits with the percentages associated.

Step-by-step explanation:

For this case we know that the random variable of interest is the scores on a test given to all juniors in a school district follows a normal distribution with the following parameters:

$X \sim N(\mu= 74, \sigma =8)$

For this case we know from the empirical rule that within one deviation from the mean we have approximately 68.2% of the data, within 2 deviations from the mean we have 95% and within 3 deviation 99.7%

We can find the limits and we got:

$\mu -\sigma = 66 , \mu +\sigma = 82$

$\mu -2\sigma = 58 , \mu +2\sigma = 90$

$\mu -3\sigma = 50 , \mu +3\sigma = 98$

And in the figure attached we see the limits with the percentages associated.

7 0

4 years ago

Drag and drop formal proof. Prove the Polygon Exterior Angle Sum Theorem for the enclosed triangle, that is ∠1+∠2+∠3=360°

jasenka [17]

Answer:

The sum of all the external angles of a triangle is 360°.

Step-by-step explanation:

Let there are n sides in a polygon.

So, there are n internal angles in the polygon, let ∠i1, ∠i2, ∠i3, ..., ∠in are the measure of n internal angles of the polygon.

The measure of external angle corresponding to ∠i1, ∠1= 180°-∠i1,

The measure of external angle corresponding to ∠i2, ∠2 = 180°-∠i2,

Similarly, the measure of external angle corresponding to ∠in, ∠n = 180°-∠in.

Now, the sum of all the external angles of the polygon,

(∠1+∠2+...+∠n)=(180°-∠i1)+(180°-∠i2)+...+(180°-∠in)

=(180°+180°+...n times)-(∠i1+∠i2+...+∠in)

=n x 180° - (∠i1+∠i2+...+∠in)

As ∠i1+∠i2+...+∠in is the sum of all the internal angles of the polygon.

So, the sum of all the external angles of the polygon =

(n x 180°) - (sum of all the internal angles of the polygon).

In the case of a triangle, n=3 and the sum of all the three internal angles, ∠i1+∠i2+∠i3 = 180°.

Therefore, the sum of all the external angles of a triangle,

∠1+∠2+∠3 =3x180°-(∠i1+∠i2+∠i3)

=540°=180°

=360°.

Hence, the sum of all the external angles of a triangle is 360°.

5 0

3 years ago

A building was planned to be built in an area north of 8th Street and east of Main Street, as shown below.

dalvyx [7]

Answer:

D

Step-by-step explanation:

4 0

3 years ago

Solve for x: 4(2x − 1) = 2x + 35

PilotLPTM [1.2K]

X = 13/2 or 6 1/2. Hope this helps!

7 0

4 years ago

Read 2 more answers

Please show work

OlgaM077 [116]

Answer:

3.7hours

Step-by-step explanation:

Step one:

A car travels 360 miles in 8 hours

the speed is calculated as

speed= distance/time

speed= 360/8

speed= 45mph

Step two:

How much time will it take traveling 168 miles?

having found the speed, which is the rate at which the car is tavelling

time= distance/speed

time= 168/45

time= 3.7hours

8 0

3 years ago

A, B, C, D, or E????​

A, B, C, D, or E????