I need to know the answer and explaining how to do it please

Answer:

Approximately 68% of students study between 22.9 and 25.7 hours.

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

Approximately 68% of the measures are within 1 standard deviation of the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean.

Approximately 99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean of 24.3 hours, standard deviation of 1.4 hours.

What percent of students study between 22.9 and 25.7 hours?

22.9 = 24.3 - 1.4

25.7 = 24.3 + 1.4

Within 1 standard deviation of the mean, so:

Approximately 68% of students study between 22.9 and 25.7 hours.

Answer:

6b=18

b=18/6

b=3

.

.

.

.

.

.

Answer:

6b=18

b=18/6

b=3

.

Step-by-step explanation:

Answer:

f(x)=-x when x belongs to (-infinity, 3)

f(x)=-2 when x belongs to [3, 6]

f(x)=2x-7 when x belongs to (6, infinity)

there are 7 vertices in this shape

Answer:

7.

Step-by-step explanation:

The vertices are the points where the lines meet.

Answer:

x=-2

Step-by-step explanation:

3x+8x - 3 = -25

Combine like terms

11x -3 = -25

Add 3 to each side

11x -3+3 = -25+3

11x = -22

Divide by 11

11x/11 = -22/11

x = -2

[tex]\large\bf{\pink{ \longrightarrow \: }} \tt \:3x \: + \: 8x \: - \: 3 \: = \: - 25[/tex]

[tex]\large\bf{\pink{ \longrightarrow \: }} \tt \:11x \: - \: 3 \: = \: - 25[/tex]

[tex]\large\bf{\pink{ \longrightarrow \: }} \tt \:11x \: = \: - 25 \: + \: 3[/tex]

[tex]\large\bf{\pink{ \longrightarrow \: }} \tt \:11x \: = \: - 22[/tex]

[tex]\large\bf{\pink{ \longrightarrow \: }} \tt \: x \: = \: {\cancel\frac{ {- 22} \:^{ - 2} }{11}} \\ [/tex]

[tex]\large\bf{\pink{ \longrightarrow \: }} \tt \:x \: = \: - 2[/tex]

Answer:

0.0244 = 2.44% probability that the mean of the sample would differ from the population mean by greater than 3.4 watts.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Mean of 102, standard deviation of 12:

This means that [tex]\mu = 102, \sigma = 12[/tex]

Sample of 63:

This means that [tex]n = 63, s = \frac{12}{\sqrt{63}}[/tex]

What is the probability that the mean of the sample would differ from the population mean by greater than 3.4 watts?

Below 102 - 3.4 = 98.6 or above 102 + 3.4 = 105.4. Since the normal distribution is symmetric, these probabilities are equal, and thus, we find one of them and multiply by two.

Probability the mean is below 98.6.

p-value of Z when X = 98.6. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{98.6 - 102}{\frac{12}{\sqrt{63}}}[/tex]

[tex]Z = -2.25[/tex]

[tex]Z = -2.25[/tex] has a p-value of 0.0122.

2*0.0122 = 0.0244

0.0244 = 2.44% probability that the mean of the sample would differ from the population mean by greater than 3.4 watts.

Answer:

z=9

Step-by-step explanation:

z-5=4. /+5

z=4+5

z=9

Answer:

z<-1

Step-by-step explanation:

5<z=4

collect like terms

z=<4-5

z<-1

Step-by-step explanation:

The photo above is the Venn diagram

Now, the number of persons that are both managers and engineers= n

Since, Total number of persons is 50

Therefore, 50= M+n+E

M only = 36-n

E only = 24-n

Therefore, 50= 36 - n + n + 24 - n

50 = 36+24-n

50 = 60 - n

60 - n = 50

-n = 50 - 60

-n = - 10

Therefore, n = 10

Therefore, the number of persons that are both Managers and Engineers is 10persons.

Step-by-step explanation:

I hope it helped and it is easy to understand i hope it was helpful

1)4y-2=8-2y+4y

=4y-2y+4y=8-2

2y +4y=8-2

6y+6

12

Answer:

B

Step-by-step explanation:

The sum of all of them will result in 180. 15x-45=180. x=15. P=55, Q=70 and R=55. It's an isosceles triangle

Answer:

b

Step-by-step explanation:

its b

Answer:

F F → F

Step-by-step explanation:

The statement is given as:

A triangle has four sides, and a rectangle has three sides.

It is again a false statement since a triangle is a polygon with three sides and a rectangle is a polygon with four sides.

Hence, the answer is:

                F  F → F

9514 1404 393

Answer:

  9

Step-by-step explanation:

If x is the number of 10-inch stones, then (x-1) is the number of 5-inch stones, and the total width is ...

  10x +5(x-1) = 130

  15x -5 = 130 . . . . . . . eliminate parentheses

  15x = 135 . . . . . . add 5

  x = 9 . . . . . . . divide by 15

Wesley will need 9 10-inch stones for one row.

Answer:

PQR+SQR=180°(angles in a triangle)

75°+SQR=180°

SQR=180°-75°

SQR=105°

Answer:

Step-by-step explanation:

a) Probability-Above 30 min = 5.72% = .0572

b) Probability-Above 15 min =  99.11% = .9911

c) *Probability-Between  1 - 59.49% = .4051

d) 19.136 minutes  z = -1.28

a) The probability that trip will take at least 1/2 hour will be 0.0606.

b) The percentage of time the lawyer is late for work will be 99.18%.

c) The probability that lawyer misses coffee will be 0.3659.

d) The length of time above which we find the slowest 10​% of trips will be 0.5438.

e) The probability that exactly 2 out of 3 trips will take at least one half

1/2 hour is 0.0103.

What do you mean by normal distribution ?

A probability distribution known as a "normal distribution" shows that data are more likely to occur when they are close to the mean than when they are far from the mean.

Let assume the time taken for a one way trip be x .

x ⇒ N( μ , σ ²)

x  ⇒ N( 24 , 3.8 ²)

a)

The probability that trip will take at least 1/2 hour or 30 minutes will be :

P ( x ≥ 30)

= P [ (x - μ) / σ ≥ (30 - μ) / σ ]

We know that , (x - μ) / σ = z.

= P [ z ≥ (30 - 24) / 3.8)]

= P [ z ≥ 1.578 ]

= 1 - P [  z ≤ 1.578 ]

Now , using the standard normal table :

P ( x ≥ 30)

= 1 - 0.9394

= 0.0606

b)

The percentage of the time the lawyer is late for work will be :

P ( x  ≥ 15)

= P [ z ≥ -2.368 ]

= P [  z ≤ 2.368]

= 0.9918

or

99.18%

c)

The probability that lawyer misses coffee :

P ( 15 < x < 25 ) = P ( x < 25 ) - P ( x < 15)

= P [  z < 0.263] - P ( z < -2.368)

or

= 0.3659

d)

The length of time above which we find the slowest 10​% of trips :

P( x ≥ X ) ≤ 0.10

=  0.5438

e)

Let's assume that y represents the number of trips that takes at least half hour.

y ⇒ B ( n , p)

y ⇒ B ( 3 , 0.0606)

So , the probability that exactly 2 out of 3 trips will take at least one half

1/2 hour is :

P ( Y = 2 )

= 3C2 × (0.0606)² × ( 1 - 0.0606)

= 0.0103

Therefore , the answers are :

a) The probability that trip will take at least 1/2 hour will be 0.0606.

b) The percentage of time the lawyer is late for work will be 99.18%.

c) The probability that lawyer misses coffee will be 0.3659.

d) The length of time above which we find the slowest 10​% of trips will be 0.5438.

e) The probability that exactly 2 out of 3 trips will take at least one half

1/2 hour is 0.0103.

Learn more about normal distribution here :

https://brainly.com/question/26822684

#SPJ2

We have,

[tex]a:b=3:6,a+b=96[/tex]

Introduce variable [tex]x[/tex] such that [tex]a=3x,b=6x[/tex]

The sum [tex]a+b=96[/tex] is therefore [tex]9x=96\implies x=10.\overline{6}[/tex]

So,

[tex]a=3\cdot10.\overline{6}=\boxed{32}[/tex] (sadia's age)

[tex]b=6\cdot10.\overline{6}=\boxed{64}[/tex] (father's age)

Hope this helps :)

Answer:

7,675

that is your answer

Step-by-step explanation:

2., 3., 4., 5.

yes, you had the right idea to calculate the half distances between the coordinates. just create the absolute values of the full distance before cutting it in half.

you need to remember : we have to go this half distance from one point to the other (meaning adding our subtracting the half distance to/from the starting point).

2.

(-4, 6) to (10, -10)

in x the distance is 10 - -4 = 14. half is 7.

in y the distance is |-10 - 6| = |-16| = 16. half is 8.

so the midpoint is

(-4 + 7, 6 - 8) = (3, -2)

remember, to go the half distance in the direction towards the second point (so we have to choose properly, when to use "+" and "-" depending on the change of the coordinate : from -4 to 10 we have to add, from 6 to -10 we have to subtract, of course).

3.

(-3, -8) to (-6.5, -4.5)

in x distance : -3 - -6.5 = 3.5. half is 1.75

in y distance : -8 - -4.5 = |-3.5| = 3.5. half is 1.75

midpoint is

(-3 - 1.75, -8 + 1.75) = (-4.75, -6.25)

4.

(3, 7) to (-8, -10)

x : 3 - -8 = 11. half is 5.5

y : 7 - -10 = 17. half is 8.5

midpoint is

(3 - 5.5, 7 - 8.5) = (-2.5, -1.5)

5.

(-6, -13) to (-6.4, -3.8)

x : -6 - -6.4 = 0.4. half is 0.2

y : -13 - -3.8 = |-9.2| = 9.2. half is 4.6

midpoint is

(-6 - 0.2, -13 + 4.6) = (-6.2, -8.4)

6.

(-1, 7) to (5, 1)

x : -1 - 5 = |-6| = 6. 1/3 is 2.

y : 7 - 1 = 6. 1/3 is 2.

1/3 from C to D

(-1 + 2, 7 - 2) = (1, 5)

7.

2/3 of the way from D to C is the same point as in 6. (1/3 from C to D).

again

(1, 5)

8.

2/3 of the way from C to D.

so, we need to double what we added in 6.

(-1 + 4, 7 - 4) = (3, 3)

9.

1/3 of the way from D to C is the same point as in 8. (2/3 of the way from C to D).

again

(3, 3)

10.

exactly. Pythagoras.

the square root of the sum of the squares of the coordinate differences.

distance = sqrt((x1 - x2)² + (y1 - y2)²)

11.

(6, 8) to (-1, 8)

distance = sqrt((6 - -1)² + (8 - 8)²) = sqrt(49) = 7

12.

(5, -6) to (5, 6)

sqrt((5-5)² + (-6-6)²) = sqrt(144) = 12

13.

(-2, 0) to (11, 0)

sqrt((-2 - 11)² + (0-0)²) = sqrt(169) = 13

14.

(1, -5) to (9, 1)

sqrt((1-9)² + (-5 - 1)²) = sqrt(64 + 36) = sqrt(100) = 10

15.

ST and MT are basically the same equation.

MT is half of ST.

ST equation based on 2 points :

y – yS={(yT – yS)/(xT – xS)}(x – xS)

M = (xS + (xT - xS)/2, yS +(yT - yS)/2)

so, let's put that into the general equation :

y - yM={(yT - yM)/(xT - xM)}(x - xM)

y - (yS +(yT - yS)/2) = {(yT - (yS +(yT - yS)/2))/(xT - (xS + (xT - xS)/2))}(x - (xS + (xT - xS)/2))

16.

the two corners farthest away are (5, 10) and (9, 6).

what distance from (0, 0) is now bigger ?

since it is (0, 0), we can skip the 0s and just sum up the squares of the coordinates.

5² + 10² = 125

9² + 6² = 117

so, the corner (5, 10) is the farthest away.

Answer:

the answer should be B

Step-by-step explanation:

take the total of people who got the flu(63) and the amount of them who were vaccinated(35) and write it as a fraction. 35/63 in its simplest form is 5/9

Answer:

35

Step-by-step explanation:

We are adding 8 and then subtracting 2

3, 11, 9, 17, 15, 23, 21

The 8th number is 21+8 = 29

The 9th number

Subtract 2

29-2 = 27

10th number

Add 8

27+8 = 35

First is adding 8 to get the next number then subtract 2 to get the number after.

21 is the 7th number.

8th number = 21 + 8 = 29

9th number = 29-2 = 27

10th number = 27 + 8 = 35

Answer: 35

Answer:

option D

Step-by-step explanation:

Area of the square is 100 m² so each side is √100 = 10 m and half the area is 50 m²

Area of one quarter of the circle is ¼πr² = ¼π(10²) = 25π

The shaded area is thus (25π - 50) m²

Answer:

2.67

Step-by-step explanation:

To solve this problem do 16.02 / 6.

Answer:

128.57 degrees

Step-by-step explanation:

To find the measure of an interior angle of a regular polygon with [tex]n[/tex] sides, we can use the formula: [tex]\frac{180(n-2)}{n}[/tex]

To find the measure of an interior angle of a polygon with 7 sides, all we have to do is plug in 7 into the formula:

[tex]\frac{180(7-2)}{7}[/tex]

7 minus 2 equals 5, so the answer is

[tex]180(5)[/tex]÷[tex]7[/tex]

180 times 5 is equal to 900, and 900 divided by 7 is approximately 128.57

Answer:

The answer is "18".

Step-by-step explanation:

In the given graph by concluding we observe that  on the x-axis, one step is 2 units, and when we half each of the steps it will= 1 unit

[tex]\therefore\\\\CD = distance\ from\ -(8+1)\ to\ (8+1)\ = \text{distance between} -9 \ to\ 9\ = 18[/tex]

Answer:

start on (0,1) and go up two and left three. keep going until you run out of room. then, draw a line through the points.

Step-by-step explanation:

Answer:

3.2 millimeters

Step-by-step explanation:

1/8*2.54 *10 = 3.175

= 3.2 millimeter. (rounded to nearest tenth)

Answer:

524cm^2

Step-by-step explanation:

Formula for Volume of sphere= 4/3 πr^2

We have,

r=5cm

Now,

Volume(v)=4/3 πr^2 = 4/3π 5^3= 4/3π 125 = 166.666666667π = 523.598775599

Rounding to the nearest tenth,

Volume=524cm^2

Answer:

32.70

Step-by-step explanation:

round up

Answer:i think it is b not really sure      

Step-by-step explanation:

Answer:

Step-by-step explanation:

P = 1800

R = 10%

T = 2 years

I = PRT

= 1800 * 10/100 * 2

= 1800 * 0.1 * 2

I = £360

The amount that will be gotten back as interest will be £360

Principal =  £1800

Rate = 10%

Time = 2 years

Simple Interest will be calculated as:

= (P × R × T) / 100

= (£1800 × 10 × 2)/100

= £36000/100

= £360

Therefore, the interest is £360.

Read related link on:

https://brainly.com/question/24355322

Answer: 1,526.04 yd³ (this is what i got on my calculator others may vary use any rounding you need)

VOLUME of CONE is: V= Pir² h / 3

Pi= 3.14

r= 9

h= 18

V= (3.14) x (9)² x (18)

9²= 81

3.14 x 81= 254.34 x 18= 4,578.12

4,578.12 / 3= 1,526.04 <-- answer