On the SAT exam, a total of 25 minutes is allotted for students to answer 20 math questions without the use of a calculator. A guidance counselor would like to know if the students in his school are prepared to complete this portion of the exam in the time allotted. To investigate, the counselor selects a random sample of 35 students and administers this portion of the test. The students are instructed to turn in their test as soon as they have completed the questions. The mean amount of time taken by the students is 23.5 minutes with a standard deviation of 4.8 minutes. The counselor would like to know if the data provide convincing evidence that the true mean amount of time needed for all students of this school to complete this portion of the test is less than 25 minutes. What are the appropriate hypotheses?

H0: μ = 23.5 versus Ha: μ < 23.5, where μ = the true mean amount of time needed for students of this school to complete this portion of the exam
H0: μ = 23.5 versus Ha: μ > 23.5, where μ = the true mean amount of time needed for students of this school to complete this portion of the exam
H0: μ = 25 versus Ha: μ < 25, where μ = the true mean amount of time needed for students of this school to complete this portion of the exam
H0: μ = 25 versus Ha: μ > 25, where μ = the true mean amount of time needed for students of this school to complete this portion of the exam

Answers

Answer 1

Answer:

H0: μ = 23.5 versus Ha: μ < 23.5, where μ = the true mean amount of time needed for students of this school to complete this portion of the exam

Answer 2

The hypothesis is H0: μ = 25 versus Ha: μ < 25, So option (C) is the correct answer.

What is mean and standard deviation?

Mean is the ratio of the sum of all the observations and the total number of observations in a data set. The standard deviation is a statistic that measures the dispersion of a data set relative to its mean and is calculated as the square root of the variance.

For the above suituation,

There are 20 math questions to be answered in 25 minutes.

After investigation with 35 students, the meantime needed for them is 23.5 and the standard deviation is 4.8.

From the above information, we can say that the hypothesis, H0: μ = 25 versus Ha: μ < 25, where μ = the true mean amount of time needed for students of this school to complete this portion of the exam.

Hence we can conclude that the hypothesis (C) is the correct answer.

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Related Questions

PLS HELP FROM 4 THROUGH 9 I BEG U PLEASEEEE

Answers

Answer:

4. 33 = 33

5. 19 > 10

6. 1 = 1

7. 0.95 > 0.9

8. 39 > 38

9. 14 > 2

10. x = 4

11. m = 44

12. p = 3

13. [tex]z=\frac{15}{23}[/tex]

4.) = equal to
5.) > greater than
6.) = equal to
7.) > greater than
8.) < less than
9.) = equal to

Whats the answer to this?

Answers

Answer:

15 degrees

X is an Acute Angle

Step-by-step explanation:

x+ 75 = 90

x =15

help ASAP!!!

The Great Pyramids of Khufu is located in El Giza, Egypt. Pyramids were built to serve as tombs for the pharaohs of ancient Egypt. The Great Pyramid is 481
feet high and has a square base with a base edge length of 756 feet. What is the approximate surface area (to the nearest hundredth) of the pyramid.
(HINT: Is the base on the surface?)​

Answers

[tex] \huge \frak \orange {question:-}[/tex]

The Great Pyramids of Khufu is located in El Giza, Egypt. Pyramids were built to serve as tombs for the pharaohs of ancient Egypt. The Great Pyramid is 481 feet high and has a square base with a base edge length of 756 feet. What is the approximate surface area (to the nearest hundredth) of the pyramid.

(HINT: Is the base on the surface?)

[tex] \huge \frak \red{solution:-}[/tex]

Square with edge length = 756 feet

Square= 1/2 × 297.45 × 481

= 286,146.9ft

= 1,037,709,9ft. base with edge length =756 feet

area of square,

= Side² = 756 × 756 = 571,563ft²

⇒ area of base = 1/2 = 756/2 = 378ft

By pythagorean theorem,

H² = P²+B²

(481)² = P²+(378)²

P² = (481)²-(378)²

P² = 231,361-142,884

P² = 88,477

P = √88,477

P = 297.45

Area of triangle =1/2 × b × h

= 1/2x297.45*481

= 148.725×481

= 71,536.725

Now area of 4 triangles = 4×71,536.725

= 286,146.9ft

total surface area of pyramid + square

= 751,563+286,146.

= 1,037,709,9ft.

[tex] \huge \frak \blue{answer:-}[/tex]

[tex] \boxed{1,037,709,9ft}[/tex]

30 in.
10 in.
10 in.
30 in
20 in
Find the area of the arrow above.
square inches

Answers

Answer:

1100 Inches Squared

Step-by-step explanation:

Let the triangle on the top right be - (i)

Let the triangle on the top left be - (ii)

Let the bottom rectangle be - (iii)

1) The base of the triangle (i) = 10 + (20/2) (It is the base of the rectangle halfed + the given amount of half base of the triangle)

=> 10 + 10

=> 20 in

Base = 20 in

Height = 30 in

Area = 1/2 * 20 * 30

=> 10 * 30

=> 300 in

Triangle (i) = (ii)

So, the area of triangle (ii)

=> 300 in

Area of rectangle,

Length * Breadth

=> 20 * 30

=> 500 in

Total arrow's area = 300 + 300 + 500 (i + ii + iii)

=> 1100

Therefore the total area of the shape = 1100 in squared.

Hope it helps :)

What is the value of 3n +1 when n = 4?
A. 12
B. 13
C. 7
D. 8​

Answers

Answer:

B. 13

Step-by-step explanation:

3(4) + 1 = 13

Answer:

13

Step-by-step explanation:

3n=3x4=12

12+1=13

Please HELP if you can!

A sample of automobile dealerships found that 19% of automobiles sold are silver. If two cars are randomly selected, what is the probability that the color of the first car is silver and the color of the second car is also siver?
A. 0.361
B. 0.0361
C. 0.380
D. 0.190

Answers

Answer:

C 0.0361

Step-by-step explanation:

The probability that the color of the first car is silver and the color of the second car is also siver is 0.0361.

Given that,

A sample of automobile dealerships found that 19% of automobiles sold are silver.The color of the first car is silver and the color of the second car is also siver.

Based on the above information, the calculation is as follows:

[tex]= 0.19\times 0.19[/tex]

= 0.0361

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If 50% of the basketball players scored fewer than 8 points in the tournament, what is the approximate probability that a basketball player
who practiced for more than 3 hours scored fewer than 8 points?
A. 0.04
B. 0.05
C. 0.10
D. 0.12

Answers

Step-by-step explanation:

A because you divide shshehxyhdjdhxhdhd

Help for brainlest if right

Answers

I think it’s B. 2x9 is 18. then 18 times 15.

If ∠2 is 70˚, what is the measure of ∠1?

Answers

110 degrees. 180-70=110

drag each expression to show whether it is equivalent to 3 time times 9 or to 2x3x9​

Answers

Answer:

The answers to your questions are given below

Step-by-step explanation:

A. 3 × 9 = 27

B. 2 × 3 × 9 = 54

Next, we shall determine which option will give the same result obtained above.

9 × 3 = 27

9 × 3 × 2 = 54

3 × (4 + 5) = 3 × 9 = 27

(2 × 3) × 9 = 6 × 9 = 54

Therefore,

3 × 9 = 27

9 × 3 = 27

3 × (4 + 5) = 27

2 × 3 × 9 = 54

9 × 3 × 2 = 54

(2 × 3) × 9 = 54

SUMMARY

3 × 9 >>>>>>>>> 2 × 3 × 9

9 × 3 >>>>>>>>> 9 × 3 × 2

3 × (4 + 5) >>>>> (2 × 3) × 9

In the above figure, m∠P = 125° and m∠Q = (5x)°. If angles P and Q are supplementary angles, what are the value of x and the measure of angle Q?

Answers

Answer:

I had the same question and the answer is x = 11, m∠Q = 55°

The value of x is 11 and measure of <Q is 55 degree.

What are supplementary angle?

Angles that add up to 180 degrees are referred to as supplementary angles. For instance, angle 130° and angle 50° are complementary angles since the sum of these two angles is 180°.

We have,

m∠P = 125° and m∠Q = (5x)°.

and, P and Q are supplementary angles.

Using the property of Supplementary Angle

<P + <Q = 180

125 + 5x= 180

5x = 55

x= 11

Thus, the measure of <Q

= 5x

= 55 degree

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Ok here is the question I need it answered fast I'll give brainliest!

Answers

Answer:

It’s C!!!

Explanation: have an amazing day!

Which function is continous across its domain? Pls help

Answers

Answer:

Step-by-step explanation:

A function f is continuous on its domain D if f is continuous at every point c∈D. Example 1. The function f(x)=ex (with domain R) is continuous on its domain.

How do I solve this?

Answers

Answer:

Step-by-step explanation:

From the picture attached,

Addition of the blocks in first row is 60

a + a + a + 12 = 60

3a + 12 = 60

3a = 60 - 12

3a = 48

a = 16

For second row,

(b + 5) + (b + 5) + (b + 5) + (b + 5) = 60

4(b + 5) = 60

b + 5 = 15

b = 10

For third row,

(a + b) + c = (b + 5) + (b + 5) + (b + 5)

a + b + c = 3(b + 5)

16 + 10 + c = 3(10 + 5) [Since, a = 16 and b = 10}

26 + c = 45

c = 45 - 26

c = 19

For fourth row,

3c + d = 60

3(19) + d = 60

57 + d = 60

d = 60 - 57

d = 3

cos x = 4/5, cos y = 24/25, find tan(x+y)

Answers

Answer:

1 19/25

Step-by-step explanation:

4

5

+  

24

25

=  

4 × 5

5 × 5

+  

24

25

=  

20

25

+  

24

25

=  

20 + 24

25

=  

44

25

=  

1 19

25

What is the correct answer?

Answers

Green 36 because you set 2x-8 = 64 and solve by adding 8 to both sides and getting 72 and dividing that by 2 which is 36

Find the surface area of the
triangular prism.
8 m
6 m
7 m.
10 m
[?] sq m.
ntar

Answers

Answer:

216

Step-by-step explanation:

The triangular prism given here is consisting of two triangles and three rectangles

So the area of the triangular prism = area of the two triangles and the area of the three rectangles

= Surface Area ₚᵣᵢₛₘ =[2 ×1/2×8×6] m²+[3×7×10]m²

= (48+210)m²

= 258m² (ans)

If two sides in a triangle are congruent, the angles opposite the congruent sides are congruent angles.

True or False

Please make an answer and give brainliest and more points to 100 need it please!
Thank you

Answers

Answer:

True

Step-by-step explanation:

Two triangles are congruent if they satisfy any of the following:

Two sides and the included angle of one triangle equal to the corresponding parts of the other one.

Two angles and the included side of one triangle equal to the corresponding parts of the other one.

All three sides of one triangle equal to the corresponding parts of the other one.

They are right triangles, and hypotenuse and one leg of one triangle equal to the corresponding parts of the other one.

They are right triangles, and hypotenuse and one acute angle of one triangle equal to the corresponding parts of the other one.

Therefore, the answer is true.

Nice Question

Answer To It is True

Reason:- According To Isosceles Triangle Theorem:-

If two angles of a triangle are congruent, then sides opposite those angles are congruent.

Hope This Helps You ❤️

A quantity with an initial value of 7200 decays exponentially at a rate of 0.3% every
day. What is the value of the quantity after 10 weeks, to the nearest hundredth?

Answers

Answer:5834.36 You're welcome

Answer:5834.36

Step-by-step explanation:

13. A square based cuboid has a width of 4cm. If the volume of the cuboid is 400 cubic
centimeters, what is the surface area of the cuboid?

Answers

Answer:

216 cm²

Step-by-step explanation:

Applying,

V = lwh..................... Equation 1

Where V = volume of the cubiod, l = length of the base, width of the base, h = heigth of the cubiod.

From the question,

Since the base of the cubiod is squared,

Therefore,

w = l = 4 cm, V = 400 cm³

Substitute these values into equation 1

400 = 4×4×h

h = 400/(4×4)

h = 25 cm

A = lw+lh+wh.................. Equation 1

Where A = surface area of the cuboid.

Given: l = 4 cm. w = 4 cm, h = 25 cm

Substitute these values into equation 1

A = (4×4)+(4×25)+(4×25)

A = 16+100+100

A = 216 cm²

<6 and <7 can be classified as:
A. alternate exterior angles
B. same-side interior angles
c. alternate interior angles
D. vertical angles

Answers

Answer:

Vertical angles

Step-by-step explanation:

I just think that's the answer

have a great rest of ur day though

I need help on this and if you the first person to answer this correctly then I would mark you BRANILIST​​​

Answers

Answer:

60

Step-by-step explanation:

Answer:

17

Step-by-step explanation:

[tex] \sqrt{300 } = 17.32[/tex]

Round to the nearest whole number which is 17.

In a file of 10 records with 2 errors, 5 are examined. Let the random variable be the number of errors.​

Answers

Jasjjhahahahwhwjwjwjwj

Find the area of the shaded region.
00
please help!! i will mark brainliest, no links please!!

Answers

Answer:

180 i think

hope it helped

Answer:

area = 118.04 units²

Step-by-step explanation:

area of circle = πr² = (3.14159)(8²) = 201.06 units²

area of triangle:

corner angle - 60°/2 = 30°

sin 30° = m/8, m = 4

height of triangle = 4 + 8 = 12

cos 30° = n/8, n = 6.93, n = 1/2 base

base of triangle = 13.86

area of triangle = 1/2bh = 1/2(13.86)(12) = 83.02 units²

area of shaded portion = 201.06 - 83.02 = 118.04 units²

k heres the actual question

Answers

Answer:

It's most likely spposed to be 22

Step-by-step explanation:

Answer: 91.65

Part 1: You will need to find the average by adding 108, 72, and 95. This will give you 275. Now you divide the sum by the amount of numbers there are which is 3 numbers. 275/3 would be 91.6

Part 2: Now that you have all four numbers you should repeat the process, 108 + 72 + 95 + 91.6 which is 366.6 now divide by four, and you have 91.65.

Let me know if this was correct!

The equation of the line of best fit is y=3x+2. x=the number of ice cream sales and y= the number of days. Answer the following questions.
Show your work as proof.
a. How many days did it take, if the number of ice cream sales is $40?
b. How much ice cream was sold on the eight day?

Answers

Answer:

all I know is how to get y but y=122

Step-by-step explanation:

y=3(40)+2

y=120+2

y=122

sorry but I dont know what to do for x

A gym owner has some purple weights and some white weights. The purple weights are 10 kilograms each, and the white weights are 6 kilograms each. The owner has 12 weights, and they weigh 84 kilograms in all. How many of each colour weight does he have?

Answers

Answer: [tex]3,9[/tex]

Step-by-step explanation:

Given

A gym owner has purple and white weights that measure 10 kg and 6 kg each

respectively.

They weigh 84 kg in total

suppose there x purple and y white weights

[tex]\therefore x+y=12\quad \ldots(i)\\\Rightarrow 10x+6y=84\quad \ldots(ii)\\\\\text{Solving }(i)\ \text{and }(ii)\\\\[/tex]

[tex]x=3,\ y=9[/tex]

Thus, there are 3 purple and 9 white weights.

Which expression is equivalent to -6(3x-2/3)

Answers

Answer:

Solution given:

-6(3x-⅔)

distribute it

-18x+6*⅔

-18x+4 is a required answer.

A rock climber is standing at the edge of a cliff looking down into a valley and sees a lion laying 120 feet from
the base of the cliff. The angle of depression of the rock climber to the lion is 35º. How high is the cliff in feet?

Answers

360 degrees
Hope this helps

Evie has 9 shirts, 5 pair of pants, 3 belts, and 6 pair of shoes. How many different outfits and she make?

Answers

She can make 23 because when u add them all together

The total possible ways is 810, it means Evie can make total 810 different outfits.

Important information:

Evie has 9 shirts, 5 pair of pants, 3 belts, and 6 pair of shoes.Combination:

Number of ways to select a shirt = 9

Number of ways to select a pant = 5

Number of ways to select a belt = 3

Number of ways to select a pair of shoes = 6

The total number of different outfits is:

[tex]9\times 5\times 3\times 6=810[/tex]

Therefore, Evie can make total 810 different outfits.

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