A random sample of 25 students in a school shows that the mean number of hours of sleep per night is 7.4 and the MAD
(mean absolute deviation) is 0.4.
Select the statement that is true.
A. The mean of this sample is likely to be the same as the mean number of hours of sleep per night of all students
in the school
B. A random sample of 50 students would likely provide a more accurate estimate of the mean number of hours of
sleep per night
C. Another random sample of 25 students is likely to have a mean between 70 and 7 8.

Answer:

−21r

Step-by-step explanation:

=−r+−20r

=(−r+−20r)

=−21r

=−21r

hope this helps!! <3

Answer:

[tex] = (3209) - (1893) \\ = 1.32 \times {10}^{3} \\ = 1320[/tex]

[tex] \small{ \star{ \underline{ \blue{becker}}}}[/tex]

Answer:

1320

Step-by-step explanation:

round off

3209 ≈ 3210

1893 ≈ 1890

estimated difference = 3210 - 1890 = 1320

Answer:

False

Step-by-step explanation:

I did the E2020 assignment

Answer:

8

Step-by-step explanation:

Answer:permutations

Step-by-step explanation:

Answer:

$560

Step-by-step explanation:

Answer:

Volume = surface area

[tex]\frac{4}{3}\pi r^3 = 4\pi r^2\\\\\frac{r}{3} = 1\\r = 3[/tex]

option B

Answer: x > 20

Step-by-step explanation:

9 - x < - 11

In this scenario, we've to collect like terms in order to.wolve for x. This will be:

9 - x < - 11

- x < - 11 - 9

- x < - 20

Divide both side by -1

-x/-1 < -20/-1

When we divide by a coefficient with minus sign, the sign changes too from less than to greater than

-x/-1 < -20/-1

x > 20

Answer:

Option B

Step-by-step explanation:

Expression representing the series is,

[tex]\sum_{k=6}^{11}(2k+5)[/tex]

Here, k = Number of terms

By placing k = 6, 7, 8, 9, 10, 11 in the expression we can get the terms of the series.

For k = 6,

(2k + 5) = 2(6) + 5

            = 17

For k = 7,

(2k + 5) = 2(7) + 5

             = 19

For k = 8,

(2k + 5) = 2(8) + 5

            = 21

For k = 9,

(2k + 5) = 2(9) + 5

            = 23

For k = 10,

0(2k + 5) = 2(10) + 5

            = 25

For k = 11,

(2k + 5) = 2(11) + 5

            = 27

Therefore, expanded form will be,

17, 19, 21, 23, 25, 27

There, is a common difference in each successive to previous term,

d = 19 - 17

d = 2

Number of terms 'n' = 6

First term = 17

Sum of an arithmetic sequence is given by,

[tex]S=\frac{n}{2}[2a+(n-1)d][/tex]

Therefore, sum of the given sequence will be,

[tex]S=\frac{6}{2}[2(17)+(6-1)2][/tex]

   = 3(34 + 10)

S = 132

Option B will be the correct option.

Answer:

∠Q  = 53.13 degrees

Step-by-step explanation:

Given that ∆PQR, ∠P = 90degrees , this means that the triangle is a right angled triangle

Hence using the notation

SOH CAH TOA

where S is sine, C is cosine, T is tangent and O, A and H represents the size of the opposite, adjacent and hypotenuse sides

Considering  ∠Q and the given sides

PR=16cm is the opposite side,

PQ= 12 cm is the adjacent side hence we use TOA

Tan Q = 16/12 =

Q = Arc tan 16/12

= 53.13 degrees

Answer:

the answer would be a

Step-by-step explanation:

Answer:

36

Step-by-step explanation:

just got it correct

Step-by-step explanation:

1. 90+65= 155°

2. π+ π/6 = 7π/6 or 210°

3. 24+180=204°

4. 3π/2 + 2π/9 = (27π+4π)/18 = 31π/18

or 310°

Answer:

a. true

b. false

c. false

d. true

e. false

Step-by-step explanation:

A. true, a shape is not warped by a rotation

b. false, the points on the figure will change

c. false, the size is not affected by a rotation

d. true, the orientation changes in a rotation

e. false, the coordinate points on the figure are altered

Answer:

A- The shapes of the figure does not change.

C- The size of the figure does not change.

D- The orientation of the figure does not change

9514 1404 393

Answer:

  (a) 2 or 3

  (b) -13

Step-by-step explanation:

(a) A, B, and C are collinear if there is some constant 'c' such that ...

  B - A = c(C - A)

This will give rise to two equations in 'c' and 'k'.

  (k +1, k +4) -(0, 9) = c((2k, k+3) -(0, 9))

  (k +1, k -5) = c(2k, k -6)

And the two equations are ...

  k +1 = 2ck

  k -5 = c(k -6)

From the first, we find ...

  c = (k +1)/(2k)

From the second, we find ...

  c = (k -5)/(k -6)

Equating these expressions for c gives ...

  (k +1)/(2k) = (k -5)/(k -6)

  (k +1)(k -6) = 2k(k -5) . . . . . . . multiply by 2k(k-6)

  k^2 -5k -6 = 2k^2 -10k

  0 = k^2 -5k +6 = (k -3)(k -2)

Solutions that make the factors zero are ...

  k = 3  or  k = 2

There are two values of k that make the points collinear: 2 and 3.

__

(b) AB is parallel to CD when the slopes of the lines between them are the same

  slope of AB = (k+4 -9)/(k+1 -0) = (k -5)/(k +1)

  slope of CD = ((k +6 -(k +3))/(2k +2 -2k) = 3/2

Equating these slopes and solving for k, we get ...

  (k -5)/(k +1) = 3/2

  2(k -5) = 3(k +1)

  2k -10 = 3k +3

  -13 = k

AB is parallel to CD when k = -13.

_____

The attached shows the collinear points on the red and blue lines. The points that make parallel lines are shown on the purple lines. (The purple circles correspond to points D for k=2 and 3, so are irrelevant.) Point D is not labeled with its coordinates, (-24, -7).

Answer: a^3 · a^2 ≠ a^6 as the laws of exponents states that the multiplication rule for two exponents with the same bases equates to addition, so that a^3 · a^2 = a^3+2 = a^5.

Answer:

12

Step-by-step explanation:

divide into two shapes. the first one being 2 x 4 units and the second being 2 x 2.

2 x 4 = 8

2 x 2 = 4

8 + 4 = 12

The answer is 12 square units.

Please mark brainliest if it was correct and helped!

Answer:

12

Step-by-step explanation:

just count the blocks

brainliest please???

Answer:

Area of triangle 12 ft^2 Area of shaded region 84 ft^2

Step-by-step explanation:

area of triangle 6 x 4 / 2 =12

Shaded region 96-12= 84 ft^2

Answer: circle

Step-by-step explanation:

The shape of the cross-section is formed when a cylinder intersects the plane is a circle option (A) is correct.

In geometry, it is defined as the three-dimensional shape having two circular shapes at a distance called the height of the cylinder.

We know the volume of the cylinder is given by:

[tex]\rm V = \pi r^2 h[/tex]

The question is incomplete.

The complete question is in the picture, please refer to the attached picture.

As we know, the circle is a set of points, where each point is at the same distance from a fixed point (called the center of a circle)

As we can see in the picture the cylinder is cut by a plane that is parallel to the base of the cylinder.

The base of the cylinder is a circle.

the shape of the cross-section is formed when a cylinder intersects a

the plane is a circle.

Thus, the shape of the cross-section is formed when a cylinder intersects the plane is a circle option (A) is correct.

Learn more about the cylinder here:

brainly.com/question/3216899

#SPJ2

Answer:

1 [tex]\frac{2}{8}[/tex]

Step-by-step explanation:

The largest is 1 [tex]\frac{4}{8}[/tex], and the smallest is [tex]\frac{2}{8}[/tex]. 1 [tex]\frac{4}{8}[/tex] - [tex]\frac{2}{8}[/tex] = 1 [tex]\frac{2}{8}[/tex].

Step-by-step explanation:

answer: 3/4 or 0.75

=5 1/4 - 4 1/2

=21/4 - 9/2

= (21-9) / 4

=3/4  or 0.75

Answer:30 boys

Step-by-step explanation: There are 120 students, three-fourths are girls. Nine out of twelve is equal to three fourths, if you add a zero to the end of twelve and nine you get 90 out of 120, which is how many girls there are. If you subtract 90 from 120 you get 30 or one-fourth. The number of boys is equal to one-fourth because there is only one-foutlrth left. So, there are 30 boys.

Answer:

x = -2 ± 452i

Step-by-step explanation:

x² + 4x = 117

x² + 4x - 117 = 0

if you solve this quadratic by using the quadratic formula you get:

x = -2 ± 452i

452i is an imaginary number that equals [tex]\sqrt{-452}[/tex]

Answer:

it's 47÷4=11 3/4 will be your final answer

Answer: - 2/3 but in decimal form it is -0.6 repeating

Step-by-step explanation:

Answer:

x=28

y=28

Step-by-step explanation:

Equation 1:

Dived both sides by 0.75 to remove 3/4 from x.

(x-12)=16

Now, add 12 to both sides.

x=28

Equation 2:

Same here, divide both sides by 0.75.

y-12=16

Add 12 to both sides.

y=28

Answer:

A) -1

Step-by-step explanation:

anything raised to the zero power is 1 but if there is a negative without parentheses around it then it becomes -1

ex, (-4)° = 1

Answer:

It would be -1.

Step-by-step explanation:

This is because any postive number to the power of 0 equals 1 but since there is a negative sign, it would become -1.

Answer:

-13

Step-by-step explanation:

6-7 x 6+7

-1 x 13

-13

Answer:

6390.56

Step-by-step explanation:

[tex]AV=PV(1+\frac{i}{n})^{nt}\\10000=x(1+\frac{.065}{2})^{7*2}\\10000=1.564807232*x\\6390.53=x[/tex]

9514 1404 393

Answer:

  $6490.57

Step-by-step explanation:

The future value is given by the compound interest formula ...

  A = P(1 +r/n)^(nt)

Principal P earns annual rate r compounded n times per year for t years.

Filling in the given values, we have ...

  10000 = P(1 +0.065/2)^(2·7) = P(1.0325^14)

  P = 10000/1.0325^14 ≈ 6390.5635

You would need to deposit $6390.57 into the account to have $10,000 in 7 years.

_____

Additional comment

Using the rounded-down result of the computation will result in a value after 7 years of $9,999.99, not quite $10,000. Rounding the computed value up to $6390.57 ensures the account balance will actually be $10,000.00 after 7 years.

If the balance is rounded to the nearest penny each time interest is added, then the balance after 7 years will be exactly $10,000.00. If there is no intermediate rounding, the resulting balance will be $10,000.01.

Most of the time, the answer key doesn't pay attention to details like this. Your expected answer may be $6390.56, or $6391 if rounded to dollars.