Factor (7x^2 + 30x

Suppose the scores of students on a Statistics course are Normally distributed with a mean of 563 and a standard deviation of 37

ololo11 [35]

Answer:

47.72% of students scored between 563 and 637 on the exam .

Step-by-step explanation:

The percentage of the students scored between 563 and 637 on the exam

= The percentage of the students scored lower than 637 on the exam -

the percentage of the students scored lower than 563 on the exam.

Since 563 is the mean score of students on the Statistics course, 50% of students scored lower than 563. that is P(x<563)=0.5

P(x<637)=P(z<z*) where z* is the z-statistic of the score 637.

z score can be calculated using the formula

z*= $\frac{X-M}{s}$ where

X =637

M is the mean score (563)

s is the standard deviation of the score distribution (37)

Then z*= $\frac{637-563}{37}$ =2

P(z<2)=0.9772, which means that 97.72% of students scored lower than 637 on the exam.

As a Result, 97.72%-50%=47.72% of students scored between 563 and 637 on the exam

5 0

3 years ago

Find the value of the constant term in the expansion of x^4 (x+3/2x^2)^5

Nataly_w [17]

5 is the answer ok I'll explain

4 0

2 years ago

The summer has ended and it’s time to drain the swimming pool. 20 minutes after pulling the plug, there is still 45 000L of wate

WITCHER [35]

Answer:

a) -900 L/min

b) 63000 L

c) v = -900t +63000

d) 7200 L

Step-by-step explanation:

a) You are given two points on the curve of volume vs. time:

(t, v) = (20, 45000) and (70, 0)

The rate of change is ...

Δv/Δt = (0 -45000)/(70 -20) = -45000/50 = -900 . . . . liters per minute

__

b) In the first 20 minutes, the change in volume was ...

(20 min)(-900 L/min) = -18000 L

So, the initial volume was ...

initial volume -18000 = 45000

initial volume = 63,000 . . . . liters

__

c) Since we have the slope and the intercept, we can write the equation in slope-intercept form:

v = -900t +63000

__

d) Put the number in the equation and do the arithmetic.

When t=62, the amount remaining is ...

v = -900(62) +63000 = -55800 +63000 = 7200

7200 L remain after 62 minutes.

6 0

3 years ago

The population of Stark county this year is 7,921 people. Last year the population was 7,547 people. Find the approximate percen

Sholpan [36]

Answer:

Option (C)

Step-by-step explanation:

To determine the population we use the formula,

$P_n=P_0(1+r)^{n}$

Where $P_n$ = final population

$P_0$ = Initial population

r = percentage growth

Now we substitute these values in the formula,

$7921=7547(1+r)^1$

$\frac{7921}{7547}=(1+r)$

r = 1.0496 - 1

r = 0.0496

r = 0.05

Therefore, percentage growth of the population of Stark county is 5%.

Option (C). will be the answer.

4 0

3 years ago

The midpoint of EF is M(4,10). One endpoint is E(2,6). Find the coordinates of the other endpoint F.

Licemer1 [7]

You will need to set equations to solve for x and y coordinate.
(2+x)/2=4
2+x=8
x=6

(6+y)/2=10
6+y=20
y=14

The answer is A. (6,14)

5 0

3 years ago

Factor (7x^2 + 30x - 25)