5th grade math. correct answer will be marked brainliest

Answer:

Test statistic = - 0.851063

- 2.520463

Step-by-step explanation:

H0 : μ ≥ 15

H1 : μ < 15

Sample mean, xbar = 14.5

Sample standard deviation, s = 4.7

Sample size = 64

Teat statistic :

(xbar - μ) ÷ (s/√(n))

(14.5 - 15) ÷ (4.7/√(64))

= - 0.851063

The critical value at α = 0.05

Using the T - distribution :

Degree of freedom, df = 64 - 1 = 63

Tcritical(0.05, 63) = 1.6694

Test statistic - critical value

-0.851063 - 1.6694

= - 2.520463

Answer:

The 95% confidence interval for the mean zinc concentration in the river is between 1.75 and 3.45 grams per milliliter.

The 99% confidence interval for the mean zinc concentration in the river is between 1.48 and 3.72 grams per milliliter.

Step-by-step explanation:

95% confidence interval:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]M = 1.96\frac{2.6}{\sqrt{36}}[/tex]

[tex]M = 0.85[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 2.6 - 0.85 = 1.75 grams per milliliter.

The upper end of the interval is the sample mean added to M. So it is 2.6 + 0.85 = 3.45 grams per milliliter.

The 95% confidence interval for the mean zinc concentration in the river is between 1.75 and 3.45 grams per milliliter.

99% confidence level:

By the same logic as for the 95% confidence interval, we have that [tex]Z = 2.575[/tex]. So

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]M = 2.575\frac{2.6}{\sqrt{36}}[/tex]

[tex]M = 1.12[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 2.6 - 1.12 = 1.48 grams per milliliter.

The upper end of the interval is the sample mean added to M. So it is 2.6 + 1.12 = 3.72 grams per milliliter.

The 99% confidence interval for the mean zinc concentration in the river is between 1.48 and 3.72 grams per milliliter.

The equivalent value of the function is f ( a ) = ( 1/6 ) , when a > 3

Given data ,

Let the function be represented as f ( x )

Now , the value of f ( x ) is

f ( x ) = 1 / ( x + 2 )

Now , the value of x > 3

So , the value of f ( x ) = f ( a )

And , when x > 3

f ( 4 ) = 1 / ( 4 + 2 )

f ( 4 ) = 1 / 6

Hence , the function is f ( 4 ) = 1 / 6

To learn more about function rule click :

https://brainly.com/question/3760195

#SPJ1

Answer:

0.30 you divided the total by the number of units which is 4

Answer:

£ 0.3

Step-by-step explanation:

Given that , a pack of 4 chocolates costs £1.20. We need to find cost of one chocolate .

=> 4 chocolates costs £1.20 .

=> 1 chocolate will cost £1.20/4 = £ 0.3

Answer:

I will have to work 11 hours to take my parents to a $ 120 cost dinner, and I will have $ 1 left in return.

If I wanted to tip 15%, I would have to work 13 hours and have $ 5 left over.

In turn, to determine the money generated from an indeterminate number of hours worked, the applicable formula would be 11X = Y, where Y is the money generated and X is the number of hours worked.

Step-by-step explanation:

Since I have just gotten my first job, and I have decided I want to take my parents out for dinner to celebrate and I have anticipated it will cost approximately $ 120 for the three of us to go out for dinner, and at my job, I make an hourly wage of $ 11, to determine how many hours would I need to work to pay for the dinner, and what if I wanted to add a 15% tip, and determine if my strategy could also allow me to find out how much money and or made for any number of hours, the following calculations must be performed:

120/11 = X

10.9 = X

11 x 11 = 121

Therefore, I will have to work 11 hours to take my parents to a $ 120 cost dinner, and I will have $ 1 left in return.

(120 x 1.15) / 11 = X

138/11 = X

12.54 = X

11 x 13 = 143

Therefore, if I wanted to tip 15%, I would have to work 13 hours and have $ 5 left over.

In turn, to determine the money generated from an indeterminate number of hours worked, the applicable formula would be 11X = Y, where Y is the money generated and X is the number of hours worked.

Answer:

$919.98

Step-by-step explanation:

To solve using a financial calculator do

N=8

I/Y=10

PMT=85

FV=1000

CMPT PV get 919.98

To do by hand find the present value of the interst payments

85*(1-(1/1.1)^8)

which is 453.4687

Find the present value of the final ballon payment

1000*(1/1.1)^8

which is 466.507

take the sum

466.507+453.4678= 919.98

Answer:

See graph and explanation

Step-by-step explanation:

Assuming you mean y ≤ −x² + 2x, you graph y = −x² + 2x and then fill in the area beneath the curve of the parabola to represent the included values. See the graph for a visual.

Answer:I think 11 will be the answer

Answer:

Step-by-step explanation:

Option B is the correct answer

10 : 20

In its simplest form

1 : 2

Answer:

Total cost of the loan $55,969.8.-

Step-by-step explanation:

Giving the following information:

An amount of $32,000 is borrowed for 10 years at 5.75% Interest, compounded annually.

To calculate the total cost of the loan, we need to use the Future Value (FV) formula:

FV= PV*(1 + i)^n

PV= loan

i= interest rate

n= number of periods

FV= 32,000*(1.0575^10)

FV= $55,969.8

Answer:

4. x = 6

5. x = 31

6. x = 34

Step-by-step explanation:

4. vertical angles

- 36/6 = 6

5. supplementary angles

180 - 56 = 124

124/4 = 31

6. complementary angle

90 - 22 = 68

68/2 = 34

Answer:

4. x = 6°

5. x = 31°

6. x = 34°

Step-by-step explanation:

4. Vertical Angles theorem states that the two opposite angles formed by 2 intersecting lines are congruent.

6x = 36°

x = 36 / 6

x = 6°

5.

180° - 56° = 4x

124° = 4x

x = 31°

6.

90° - 22° = 2x

68° = 2x

x = 34°

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

Answer:

24/25

Step-by-step explanation:

on delta math

The ratio of cosine of angle X is 24/25.

Trigonometric Ratios are defined as the values of all the trigonometric functions based on the value of the ratio of sides in a right-angled.

Given a right triangle, XYZ with angle Y equals 90° and  ZY=7, XZ=24 and YX=25

The ratio of the cosine of an angle is the ratio of the base to the hypotenuse of the right triangle,

Here, Cosine of angle X = XZ/YX

cosX = 24/25

Hence, The ratio of cosine of angle X is 24/25.

For more references on trigonometric ratios, click;

https://brainly.com/question/25122825

#SPJ2

Answer:

A

Step-by-step explanation:

trust

Answer:

B.

200.96 cm2

Step-by-step explanation:

A≈201.06cm²

Solution

A=πr2=π·82≈201.06193cm²

Answer:

B. 8cm*12cm

Step-by-step explanation:

Area is the product of the two sides:

6*16 = 96

8*12 = 96

10*10 = 100

Perimeter is the sum of all four sides:

6+16+6+16 = 44

8+12+8+12 = 40

The answer is B. 8cm*12cm

Answer:

17.1≤x≤23.1

Step-by-step explanation:

The formula for calculating the confidence interval is expressed as;

CI = x ± z*s/√n

x is the mean yield = 20.1

z is the 80% z-score = 1.282

s is the standard deviation = 7.66

n is the sample size =  11

Substitute

CI = 20.1 ± 1.282*7.66/√11

CI = 20.1 ± 1.282*7.66/3.3166

CI = 20.1 ± 1.282*2.3095

CI =  20.1 ±2.9609

CI = (20.1-2.9609, 20.1+2.9609)

CI = (17.139, 23.0609)

hence the required confidence interval to 1dp is 17.1≤x≤23.1

Answer:

Option F, y = 2x + 5 would be the right answer

Hope this helps!

Answer:

Option F would be correct.

Hope this helps<3

Have a good day :)

~Amy

my best answer is B i hope this helps

Answer:

x > 2

Step-by-step explanation:

x + 1 > 3

Subtract 1 from both sides

x + 1 - 1 > 3 - 1

x > 2

Answer:

no

Step-by-step explanation:

Answer:

it's not

Step-by-step explanation:

Answer:

x = -1

Step-by-step explanation:

-3 +12 = 9

-9x = 9

-9(-1)=9

9 - 12 = -3

Answer:

x = 12

Step-by-step explanation:

It is a 90° angle which means that both of the angles need to add up to 90. 90-20 =70. 6×12 = 72.

6×9= 72

72-2 = 70

It adds up.

Hope this helps.

Answer:

x - y = 3(x + 2)

Step-by-step explanation:

The difference of x and y is the same as 3 times the sum of x and 2

x - y = 3(x + 2)

x - y = 3x + 6

Answer:

spoke out of term and with no true option.

Step-by-step explanation:

All you do is add them all up but tbh that picture could use some work and maybe when you fix it ill help you then .So the square unit of this picture is 6

It equals this graph expression. it's a little cropped, but I'm Sure you know about the y & x axis.

9514 1404 393

Answer:

  C:  5 inches

Step-by-step explanation:

The length of the sides of the new square is the square root of the area:

  s = √A = √49 = 7

The original square had sides 2 inches shorter, so they were ...

  7 in -2 in = 5 in . . . . side length of original square

Answer:

A. (-1, 0)

Step-by-step explanation:

I calculated it logically

Answer:

none of above

Step-by-step explanation:

Answer:

The probability is 0.6796

Step-by-step explanation:

Given

Population Mean - 100

Population Standard Deviation - 25

As we know

z = x-μ/σ, where:

z is the standard score

x is the raw score  

μ is the population mean

σ is the population standard deviation

Z value for mean of sample = 95

z1 = -100+95/25 = -5/25 = -0.2

P value for Z = -0.2 is 0.2912

Z2 = 100-105/25 = 0.2

P(z > 0.2 = 1 - P(z ≤ 0.2) = 1 - 0.0294 = 0.9706

P(-0.2 < z < 0.2) = 0.9706 - 0.2912= 0.6796

The probability is 0.6796