All categories

3 years ago

Pls Help!!

Mathematics

1 answer:

Studentka2010 [4]3 years ago

5 0

Answer:

Megan needs a 95 to get an average of 90.

Step-by-step explanation:

Add up the test scores Megan has earlier, you would get 355 as a result of all scores added. In order to get an average of 90%, you would need to accumulate 450 points which she will need to take her final exam on it. Subtract 355 from 450 to get a score of 95% in which she will need that score to average it to 90%.

You might be interested in

A tourist first walked 17km with a speed of v km/h. Then he hiked 12 km uphill with the speed that was 2 km/hour less than his o

ExtremeBDS [4]

Answer: $t=\frac{17}{v}+\frac{12}{v-2}$

Step-by-step explanation:

Given: A tourist first walked 17km with a speed of v km/h.

Since $Speed=\frac{distance}{time}$

therefore, $Time=\frac{distance}{speed}$

Let $t_1$ be the time he walked with speed v.

then $t_1=\frac{17}{v}$

Also he hiked 12 km uphill with the speed that was 2 km/hour less than his original speed.

Let $t_2$ be the time he hiked 12 km,

Then $t_2=\frac{12}{v-2}$

The total time for the whole trip is given by:-

$t=t_1+t_2=$

Substitute the values of $t_1$ and $t_2$ in the equation, we get

$t=\frac{17}{v}+\frac{12}{v-2}$

4 0

3 years ago

21+4(3^2-5) PLEASE ANSWER FAST

lana [24]

Step-by-step explanation:

21 + 16

HOPE THIS HELPS!

8 0

3 years ago

Read 2 more answers

A triangle can be formed with the lengths 10 cm, 5 cm and 14 cm.

Grace [21]

Answer: yes.

Step-by-step explanation: i dont really get this one so i just said yes

5 0

3 years ago

Select all the statements that are true for the graph shown.

Yuki888 [10]

Answer:

The relationship is proportional.

The relationship is linear.

The equation of the line is y = –3x.

Step-by-step explanation:

The line in the question passes through origin and (4,-12).

The rate of change of the line is

$m=\dfrac{-12-0}{4-0}\\\Rightarrow m=\dfrac{-12}{4}\\\Rightarrow m=-3$

The rate of change of the line or slope of the line is -3

Equation of the line is given by

$(y-0)=-3(x-0)\\\Rightarrow y=-3x$

This means that the relationship is linear.

If we take any value of x then there will be only one value of y this means that the relationship is proportional.

So the following statements are true

The relationship is proportional.

The relationship is linear.

The equation of the line is y = –3x.

3 0

3 years ago

Read 2 more answers

Terri Vogel, an amateur motorcycle racer, averages 129.71 seconds per 2.5 mile lap (in a 7 lap race) with a standard deviation o

Vikki [24]

Answer:

(a) The percent of her laps that are completed in less than 130 seconds is 55%.

(b) The fastest 3% of her laps are under 125.42 seconds.

Step-by-step explanation:

The random variable X is defined as the number of seconds for a randomly selected lap.

The random variable X is normally distributed with mean, μ = 129.71 seconds and standard deviation, σ = 2.28 seconds.

Thus, $X\sim N(129.71,\ 2.28^{2})$ .

(a)

Compute the probability that a lap is completes in less than 130 seconds as follows:

$P(X$

$=P(Z$

The percentage is, 0.55 × 100 = 55%.

Thus, the percent of her laps that are completed in less than 130 seconds is 55%.

(b)

Let x represents the 3rd percentile.

That is, P (X < x) = 0.03.

⇒ P (Z < z) = 0.03

The value of z for the above probability is:

z = -1.88

Compute the value of x as follows:

$z=\frac{x-\mu}{\sigma}\\-1.88=\frac{x-129.71}{2.28}\\x=129.71-(1.88\times 2.28)\\x=125.4236\\x\approx 125.42$

Thus, the fastest 3% of her laps are under 125.42 seconds.

(c)

Let x₁ and x₂ be the values between which the middle 80% of the distribution lie.

That is,

$P(x_{1}$

The value of z for the above probability is:

z = 1.28

Compute the values of x₁ and x₂ as follows:

$-z=\frac{x_{1}-\mu}{\sigma}\\-1.28=\frac{x_{1}-129.71}{2.28}\\x_{1}=129.71-(1.28\times 2.28)\\x=126.7916\\x\approx 126.80$ $z=\frac{x_{2}-\mu}{\sigma}\\1.28=\frac{x_{2}-129.71}{2.28}\\x_{2}=129.71+(1.28\times 2.28)\\x=132.6284\\x\approx 132.63$

Thus, the middle 80% of her laps are from 126.80 seconds to 132.63 seconds.

5 0

3 years ago