All categories

3 years ago

HELP HELP HELP HELP WOPFOPOPMPOMGOPRDAGS

Mathematics

1 answer:

Basile [38]3 years ago

4 0

Answer:

Step-by-step explanation:

You can't ever let this go negative. At least not at the grade you are in.

It can be 0.

So the domain must start at x = 7

sqrt(5*7 - 35) = sqrt(0) = 0

x can have any value (including 7) between 7 and infinity. If you choose a number less than 7 (like 6) the square root will go negative and that's not to be done.

So the interval is

7 ≤ x < ∞

You might be interested in

Many states assess the skills of their students in various grades. One program that is available for this purpose is the Nationa

Nataly [62]

Answer:

A score of 314 is needed to be in the top 25% of students who take this exam.

Step-by-step explanation:

We are given that one of the tests provided by the NAEP assesses the reading skills of twelfth-grade students. In recent years, the national mean score was 289 and the standard deviation was 37.

Let X = scores of the tests provided by the NAEP

The z-score probability distribution for the normal distribution is given by;

Z = $\frac{X-\mu}{\sigma}$ ~ N(0,1)

where, $\mu$ = national mean score = 289

$\sigma$ = standard deviation = 37

Now, we have to find how high a score is needed to be in the top 25% of students who take this exam, that means;

P(X > x) = 0.25 {where x is the required score}

P( $\frac{X-\mu}{\sigma}$ > $\frac{x-289}{37}$ ) = 0.25

P(Z > $\frac{x-289}{37}$ ) = 0.25

In the z table, the critial value of z that represents the top 25% of the area is given as 0.6745, that is;

$\frac{x-289}{37}=0.6745$

${x-289}=0.6745\times 37$

x = 289 + 24.96 = 313.96 ≈ 314

Hence, a score of 314 is needed to be in the top 25% of students who take this exam.

7 0

3 years ago

A 51-foot wire running from the top of a tent pole to the ground makes an angle of 58° with the ground. If the length of the ten

AfilCa [17]

Answer:

35.11 ft

Step-by-step explanation:

This given situation can be thought of as triangle $\triangle PQR$ where PQ is the length of pole.

PR is the length of rope.

and QR is the distance of bottom of pole to the point of fastening of rope to the ground.

And $\angle Q \neq 90^\circ$

Given that:

PQ = 44 ft

PR = 51 ft

$\angle R = 58^\circ$

To find:

Side QR = ?

Solution:

We can apply Sine Rule here to find the unknown side.

Sine Rule:

$\dfrac{a}{sinA} = \dfrac{b}{sinB} = \dfrac{c}{sinC}$

Where

a is the side opposite to $\angle A$

b is the side opposite to $\angle B$

c is the side opposite to $\angle C$

$\dfrac{PR}{sinQ}=\dfrac{PQ}{sinR}\\\Rightarrow sin Q =\dfrac{PR}{PQ}\times sinR\\\Rightarrow sin Q =\dfrac{51}{44}\times sin58^\circ\\\Rightarrow \angle Q =79.41^\circ$

Now,

$\angle P +\angle Q +\angle R =180^\circ\\\Rightarrow \angle P +58^\circ+79.41^\circ=180^\circ\\\Rightarrow \angle P = 42.59^\circ$

Let us use the Sine rule again:

$\dfrac{QR}{sinP}=\dfrac{PQ}{sinR}\\\Rightarrow QR =\dfrac{sinP}{sinR}\times PQ\\\Rightarrow QR =\dfrac{sin42.59}{sin58}\times 44\\\Rightarrow QR = 35.11\ ft$