A student has test scores of 75 and 82respectively. What is the student’s average score for a third test

Answer:

[tex]\bar x = 107.11[/tex]

[tex]\sigma_x = 31.07[/tex]

Step-by-step explanation:

See comment for complete question

Given

[tex]x: 97\ 178\ 129\ 90\ 75\ 94\ 116\ 100\ 85[/tex]

Solving (a): The sample mean

This is calculated using:

[tex]\bar x = \frac{\sum x}{n}[/tex]

So, we have:

[tex]\bar x = \frac{97+ 178+ 129+ 90+ 75+ 94+ 116+ 100+ 85}{9}[/tex]

[tex]\bar x = \frac{964}{9}[/tex]

[tex]\bar x = 107.11[/tex]

Solving (b): The sample standard deviation

This is calculated as:

[tex]\sigma_x = \sqrt{\frac{\sum(x - \bar x)^2}{n-1}}[/tex]

So, we have:

[tex]\sigma_x = \sqrt{\frac{(97 - 107.11)^2 +.............+ (85- 107.11)^2 }{9-1}}[/tex]

[tex]\sigma_x = \sqrt{\frac{7720.8889}{8}}[/tex]

[tex]\sigma_x = \sqrt{965.1111125}[/tex]

[tex]\sigma_x = 31.07[/tex]

Answer:

hey hi mate

hope you like it

plz mark it as brainliest

Answer:

[tex]41\text{ [units squared]}[/tex]

Step-by-step explanation:

The octagon is irregular, meaning not all sides have equal length. However, we can break it up into other shapes to find the area.

The octagon shown in the figure is a composite figure as it's composed of other shapes. In the octagon, let's break it up into:

Formulas:

Area of triangles:

All four triangles we broke the octagon into are congruent. Each has a base of 2 and a height of 2.

Thus, the total area of one is [tex]A=\frac{1}{2}\cdot 2\cdot 2=2\text{ square units}[/tex]

The area of all four is then [tex]2\cdot 4=8[/tex] units squared.

Area of rectangles:

The two smaller rectangles are also congruent. Each has a length of 3 and a width of 2. Therefore, each of them have an area of [tex]3\cdot 2=6[/tex] units squared, and the both of them have a total area of [tex]6\cdot 2=12[/tex] units squared.

The last rectangle has a width of 7 and a height of 3 for a total area of [tex]7\cdot 3=21[/tex] units squared.

Therefore, the area of the entire octagon is [tex]8+12+21=\boxed{41\text{ [units squared]}}[/tex]

Answer:

The probability that you get an even card or a spade is P = 0.596

Step-by-step explanation:

In a deck of 52 cards, all the cards have the exact same probability of being drawn.

So, the probability of drawing an even card of a spade, will be equal to the quotient between the number of even cards and spades, and the total number of cards (52).

First, let's found the number of even cards and spades.

There are 13 spades.

For each set, the even cards are:

{2. 4, 6, 8, 10}

(not counting the queen as a "12")

Then for each set, there are 6 even cards.

(there are four sets but we already counted the 6 even cards from the spade set, so we ignore that set)

Then there are 3 sets with 6 even cards each, there are:

3*6 = 18 even cards

So we have:

13 spades + 18 even cards = 31 cards that meet the condition.

The probability is then:

P = 31/52 = 0.596

The probability that you get an even card or a spade is P = 0.596

Answer:

AB = 5.6 cm

Step-by-step explanation:

Reference angle (θ) = 62°

Hypotenuse = 12 cm

Adjacent = AB

Apply the trigonometric ratio formula, CAH, which is:

Cos θ = Adj/Hyp

Plug in the values

Cos 62° = AB/12

12*Cos 62° = AB

5.63365876 = AB

AB = 5.6 cm (1 decimal place)

Answer:

A. No, because the arcs do not have the same measure.

Step-by-step explanation:

Two arcs can be said to be congruent when the length measure of the two arcs are the same and not necessarily the degree measure. This implies that two arcs can have the same degree measure measure but their length may not be the same.

If two arcs have the same measure in one circle, therefore we can say they are congruent or if they have the same measure in congruent circles respectively, they are congruent.

In the two circles given above, although we are not told if both circles are congruent, however, since both arcs have different degree measure, both arcs cannot be congruent.

Answer:I’m pretty sure ( not 100% thou ) the awnser would be A) 4

Answer:

-7

Step-by-step explanation:

if you multiply by 7 positive it wont work because u cant cancel 7x out and a fraction wont work because theres no fraction involved in this so ur answer is A

Answer:

z> -2

Step-by-step explanation:

STEP 1) Any expression divided by itself equals 1

-3z-1<5

STEP 2) Move the constant to the right-hand side and change its sign

-3z<5+1

STEP 3) Add the numbers

5+1= 6

-3z<6

STEP 4) Divide both sides of the inequality by -3 and flip the inequality sign

z>-2

Answer:

54 cm is the perimeter I think

Answer:

You don't really need to do it, but it helps you keep things more organized and easier to follow. Imagine if you're doing some multi-variable equation,

2a + 5b + 4d + 3c + b + a + 2d

that looks like a mess, it'll be easier to look at if you put all the similar variables next to each others like this:

a + 2a + b + 5b + 3c + 2d + 4d

(a + 2a) + (b + 5b) + 3c + (2d + 4d)

now you can add them up much easier.

Answer:

in a square all sides are equal so x has to equal

128

Hope This Helps!!!

Answer:

363,000,000

..........

Answer:

11 hours is right answer i hope it will help you

i)50

Steps

30+20=50

ii)7

Steps

75-(30+20)-18

=75-(50)-18

=7

iii)20

Steps

From the available data from the question

iv)30

Steps

From the available data from the questionl

v)From the attcged image file

im struggling with the same one

Answer:

[tex]z = 1.6[/tex]

Step-by-step explanation:

Given

[tex]Pr = 0.05[/tex]

Required

The z value to the right

The z value to the right is represented as:

[tex]P(Z > z)[/tex]

So, the probability is represented as:

[tex]P(Z > z) = 0.05[/tex]

From z table, the z value that satisfies the above probability is:

[tex]z = 1.645[/tex]

[tex]z = 1.6[/tex] --- approximated

Answer:

x=−40

Step-by-step explanation:

Step 1: Simplify both sides of the equation.

x4−3x8=5

14x+−38x=5

(14x+−38x)=5(Combine Like Terms)

−18x=5

−18x=5

Step 2: Multiply both sides by 8/(-1).

(8−1)*(−18x)=(8−1)*(5)

x=−40

Answer:

x=−40

Hello!

x/4 - 3x/8 = 5

2x - 3x = 40

-x = 40

x = -40

Good luck! :)

You have some data points labeled by [tex]x[/tex]. They form the set {3, 5, 7}.

The mean, [tex]\bar x[/tex], is the average of these values:

[tex]\bar x = \dfrac{3+5+7}3 = \dfrac{15}3 = 5[/tex]

Then in the column labeled [tex]x-\bar x[/tex], what you're doing is computing the difference between each data point [tex]x[/tex] and the mean [tex]\bar x[/tex]:

[tex]x=3 \implies x-\bar x = 3 - 5 = -2[/tex]

[tex]x=5 \implies x-\bar x = 5-5 = 0[/tex]

[tex]x=7 \implies x-\bar x = 7 - 5 = 2[/tex]

These are sometimes called "residuals".

In the next column, you square these values:

[tex]x=3 \implies (x-\bar x)^2 = (-2)^2 = 4[/tex]

[tex]x=5 \implies (x-\bar x)^2 = 0^2 = 0[/tex]

[tex]x=7 \implies (x-\bar x)^2 = 2^2 = 4[/tex]

and the variance of the data is the sum of these so-called "squared residuals".

Answer:

916.67 (corrected to 2 decimal places)

Hope I'm right, fingers crossed

Step-by-step explanation:

[tex]55 \times 50 = 2750 \div \frac{3}{4 } = 916.6666667[/tex]

Answer:

Attached images

It was just easier for me this way.

Let me know in comments if you have questions.

Step-by-step explanation:

Answer:

Amazon

Step-by-step explanation:

Answer:

x=2

Step-by-step explanation:

16+4=3x+7x

20=10x

20/10=10x/10

2=x

Answer:

t = 1

Step-by-step explanation:

16 - 2t = 5t + 9

7 = 7t

t = 1

9514 1404 393

Answer:

  1/3; geometric

Step-by-step explanation:

Apparently, your sequence is ...

  81, 27, 9, 3, 1, ...

The differences between these numbers vary, but the ratio of each to the one before is a constant:

  27/81 = 9/27 = 3/9 = 1/3

The sequence is geometric with a common ratio of 1/3. The next number in the sequence is (1)(1/3) = 1/3.

Answer:

[tex]X=6.67ft/s[/tex]

Step-by-step explanation:

From the question we are told that:

Height of pole [tex]H_p=15[/tex]

Height  of man [tex]h_m=6ft[/tex]

Speed of Man [tex]\triangle a =4ft/s[/tex]

Distance from pole [tex]d=35ft[/tex]

Let

Distance from pole to man=a

Distance from man to shadow =b

Therefore

 [tex]\frac{a+b}{15}=\frac{b}{6}[/tex]

 [tex]6a+6b=15y[/tex]

 [tex]2a=3b[/tex]

Generally the equation for change in velocity is mathematically given by

 [tex]2(\triangle a)=3(\triangle b )[/tex]

 [tex]2*4=3(\triangle b)[/tex]

 [tex]\triangle a=\frac{8}{3}[/tex]

Since

The speed of the shadow is given as

 [tex]X=\triangle b+\triangle a[/tex]

 [tex]X=4+8/3[/tex]

 [tex]X=6.67ft/s[/tex]

Answer:

At 4:00 PM the distance between the two ships is 104.40 kilometers.

Step-by-step explanation:

Given that at noon, ship A is 150 km west of ship B, and ship A is sailing east at 30 km / h and ship B is sailing north at 25 km / h, to determine how fast is the distance between the ships changing at 4:00 PM the following calculation must be performed:

150 - (30 x 4) = 150 - 120 = 30

0 + (25 x 4) = 0 + 100 = 100

30 ^ 2 + 100 ^ 2 = X ^ 2

√ (900 + 10,000) = X

√10,900 = X

104.40 = X

Therefore, at 4:00 PM the distance between the two ships is 104.40 kilometers.

Answer:

0 = 0

1 = 4

2 = 8

Step-by-step explanation:

So you multiply x by 4 to get y. Your first column is x. So you multiply those numbers by 4 to get y.

Answer:

0

4

8

Step-by-step explanation:

y = 4x

Substitute each x into equation to get y

y = 4(0)

y = 0

[tex]\frac{13}{28}[/tex]

Given:

Blue marbles: 3

Reb marbles: 5

Total marbles: 8

Two marbles are selected at random, one after the other with replacement.

Getting the same colour of marbles from the selection means the two marbles are both red or both blue.

(a) Probability of getting 2 marbles being red in colour

i. Probability of picking a red at the first selection:

Number of red marbles ÷ Total number of marbles

=> 5 ÷ 8 = [tex]\frac{5}{8}[/tex]

ii. Probability of picking a red at the second selection:

Number of remaining red marbles ÷ Total number of remaining marbles

Since after the first pick, the marble is not replaced, the remaining red marbles is 4 while the total number of remaining marbles is 7

=> 4 ÷ 7 = [tex]\frac{4}{7}[/tex]

iii. The probability of getting both marbles being red is the product of i and ii above. i.e

[tex]\frac{5}{8}[/tex] x [tex]\frac{4}{7}[/tex] = [tex]\frac{5}{14}[/tex]

(b) Probability of getting 2 marbles being blue in colour

i. Probability of picking a blue at the first selection:

Number of blue marbles ÷ Total number of marbles

=> 3 ÷ 8 = [tex]\frac{3}{8}[/tex]

ii. Probability of picking a blue at the second selection:

Number of remaining blue marbles ÷ Total number of remaining marbles

Since after the first pick, the marble is not replaced, the remaining blue marbles is 2 while the total number of remaining marbles is 7

=> 2 ÷ 7 = [tex]\frac{2}{7}[/tex]

iii. The probability of getting both marbles being blue is the product of i and ii above. i.e

[tex]\frac{3}{8}[/tex] x [tex]\frac{2}{7}[/tex] = [tex]\frac{3}{28}[/tex]

(c) Probability of getting 2 marbles of the same colour.

The probability of getting 2 marbles of same colour is the sum of the probability of getting both marbles of red colour and the probability of getting both marbles as blue colour. i.e The sum of a(iii) and b(iii)

[tex]\frac{5}{14}[/tex] + [tex]\frac{3}{28}[/tex] = [tex]\frac{13}{28}[/tex]

The probability of getting 2 of the same colour is [tex]\frac{13}{28}[/tex]