The weekly earnings of students in one age group are normally distributed with a standard deviation of 88 dollars. A researcher wishes to estimate the mean weekly earnings of students in this age group. Find the sample size needed to assure with 98 percent confidence that the sample mean will not differ from the population mean by more than 2 dollars.

Answers

Answer 1

Answer:

The sample size needed is of 10,484.

Step-by-step explanation:

We have 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 - 0.98}{2} = 0.01[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a p-value of [tex]1 - 0.01 = 0.99[/tex], so Z = 2.327.

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.

The weekly earnings of students in one age group are normally distributed with a standard deviation of 88 dollars.

This means that [tex]\sigma = 88[/tex]

Find the sample size needed to assure with 98 percent confidence that the sample mean will not differ from the population mean by more than 2 dollars.

This is n for which M = 2. So

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

[tex]2 = 2.327\frac{88}{\sqrt{n}}[/tex]

[tex]2\sqrt{n} = 2.327*88[/tex]

[tex]\sqrt{n} = \frac{2.327*88}{2}[/tex]

[tex](\sqrt{n})^2 = (\frac{2.327*88}{2})^2[/tex]

[tex]n = 10483.3[/tex]

Rounding up:

The sample size needed is of 10,484.


Related Questions

A train is exactly 24km from Smalltown at 7:00p.m. It travels toward Smalltown at a constant rate of 90km per hour. At what time does the train reach Smalltown?

Answers

Answer:

7:16 P.M.

Step-by-step explanation:

24/90=4/15. There are 60 minutes in an hour, so we have 240/15=16.

Find the length of the segment indicated. Round your answer to the nearest 10th of necessary.

Answers

Answer:

Step-by-step explanation:

Just using pythagorean theorem,

13.2²+16.9²=c²

174.24+285.61=c²

c²=√459.85

c= 21.4441134114

c = 21.4 (nearest tenth)

I need help
Center?
Radius?

Answers

Answers:

Center = (1, 5)

Radius = 3

===========================================================

Work Shown:

[tex]x^2+y^2-2x-10y+17 = 0\\\\(x^2-2x)+(y^2-10y)+17 = 0\\\\(x^2-2x+0)+(y^2-10y+0)+17 = 0\\\\(x^2-2x+1-1)+(y^2-10y+25-25)+17 = 0\\\\(x^2-2x+1)+(y^2-10y+25)+(-1-25+17) = 0\\\\(x-1)^2+(y-5)^2-9 = 0\\\\(x-1)^2+(y-5)^2 = 9\\\\(x-1)^2+(y-5)^2 = 3^2[/tex]

----------------------

Explanation:

The idea is to complete the square for the x and y terms separately.

Notice the jump from step 3 to step 4 has the first 0 turn into 1-1, and the second 0 turn into 25-25. This is to help complete the square for each part.

The x^2-2x+1 factors to (x-1)^2 and y^2-10y+25 factors to (y-5)^2

Once we reach the last step, we have something in the form [tex](x-h)^2+(y-k)^2 = r^2[/tex]

Center = (h,k) = (1,5)

Radius = r = 3

(√0,04-√(-1,2)²+√121)×√81

Answers

Answer:  90

Step-by-step explanation:

[tex]\displaystyle\ \Large \boldsymbol{} (\sqrt{0,04}-\sqrt{(-1,2)^2}+\sqrt{121 } ) \cdot \sqrt{81} = \\\\\\(0,2-1,2+11)\cdot 9=(11-1)\cdot 9=90[/tex]


Find dy /dx of x² - 2x + 5 - 6x

Answers

Answer:

Step-by-step explanation:

If [tex]y=x^2-2x+5-6x[/tex] then

[tex]y=x^2-8x+5[/tex] by combining like terms. (I'm thinking you might have mistyped the problem because this representation is weird).

[tex]\frac{dy}{dx}=2x-8[/tex]

If a and b are parallel and c and d are parallel, which pair of angles are congruent?

A. 1 and 16
B. 5 and 8
C. 9 and 11
D. 12 and 13

Answers

was there any pic added to this equation?

.Prove a+ar+ar2+………+arn-1=a(rn -1 ) r-1

Answers

Answer:

See below.

Step-by-step explanation:

Call the sum of the first n terms S.

S = a + ar + ar^2 + ar^3 + ... + ar^(n -1)

Multiply both sides by r.

Sr = ar + ar^2 + ar^3 + ar^4 + ... + ar^n

No subtract S - Sr.

      S =  a + ar + ar^2 + ar^3 + ar^4 + ... + ar^(n -1)

(-)    Sr =       ar + ar^2 + ar^3 + ar^4 + ... + ar^(n - 1) + ar^n

-------------------------------------------------------------------

  S - Sr = a - ar^n

S(1 - r) = a(1 - r^n)

S = a(1 - r^n)/(1 - r)

S = a(r^n - 1)/(r - 1)

a + ar + ar^2 + ar^3 + ... + ar^(n -1) = a(r^n - 1)/(r - 1)

i need serious helpplease its confusing....

Answers

area: 40p² + 24p

wide: 8p

(40p² + 24p)/ 8p

5p + 3

so, length: 5p + 3 -> (a)

perimeter = wide x 2 + length x 2

16p + (10p + 6)

26p + 6 -> (b)

Will give BRAINLIEST to the correct answer.


Angelica Reardon received a 4-year non-subsidized student loan of $18,000 at an annual interest rate of 6.8%. What are Angelicas monthly loan payments for this loan after she graduates in 4 years? (Round your answer to the nearest cent.)

Answers

Answer:

In 2021 she would have the loan of $18,000 and in 2022 she would have $13,947 and 2023 she would have $9,609 and in 2024 she would have $4,968 and in 2025 she would have $0.

The total lifetime costs of your student loans would be $20,609 paid over 4 years.

- I HOPE THIS HELPS! :)

Step-by-step explanation:

- Is a student loan calculator (2021)

-This is a very GOOD site!!!!! :)

The Angelica's monthly loan payments for this loan after she graduates in 4 year is $408.

What is simple interest?

Simple interest is a quick and easy method of calculating the interest charge on a loan.

What is the formula for calculating the simple interest?

The formula for calculating the simple interest is

[tex]Simple\ interest = \frac{P\times R\times T}{100}[/tex]

Where,

P is the principal amount

R is the interest rate

And, T is the time in years

According to the given question.

Principal amount, P = $18,000

Interest rate, R = 6.8%

Time, T = 4 years

Therefore,

The monthly loan payments, we calculate the simple interest for monthly

= [tex]\frac{18000 \times 6.8\times 4}{100 \times 12}[/tex] = $408

Hence, the Angelica's monthly loan payments for this loan after she graduates in 4 year is $408.

Find out more information about simple interest here:

https://brainly.com/question/22621039

#SPJ2

help me please its confusing

Answers

Answer:

9c^7d^13

Step-by-step explanation:

The square of y varies directly as the cube of x.When x=4 y=2.Which equation can be used to find other combinations of x and y

Answers

Answer:

y² = (1/16)x³

Step-by-step explanation:

Given that :

y² varies directly as the cube of x

y² α x³

y² = kx³ - - - (1)

Where, k = constant of f proportionality

We can obtain the value of k ; when x= 4 and y = 2

2² = k4³

4 = 64k

k = 4/64

k = 1/16

Putting k = 1/16 in (1)

y² = (1/16)x³

Write the expression 4^4(4^-7)(4) using a single
exponent.
4^-28
4^-4
4^-3
4^-2

Answers

Answer:

4^(-2)

Step-by-step explanation:

4^4(4^-7)(4)

We know that a^b * a^c = a^(b+c)

4^4(4^-7)(4^1)

4^(4+-7+1)

4^(-2)

What is the average of −18.75 and 200.25?


90.75


100.125


109.5


181.5

Answers

90.75 it the answers

what is the total cost

Answers

Answer:

u watch Naruto

Step-by-step explanation:

.....................,....,...

A viewfinder has a triangular lens. Some of the measurements of the lens are
shown below. Which of the following best represents the length of a?
B
26°
a
С
389
10
A
Triangle not drawn to scale

Answers

Answer: Choice A) 6.8 inches

=========================================================

Explanation:

It's a bit strange why your teacher has the "26 degree" label pointing at a side length, rather than an actual angle. I'm assuming your teacher meant to aim it at angle C. In other words, I'm assuming they meant to say angle C = 26 degrees.

If that assumption is correct, then,

A+B+C = 180

38+B+26 = 180

B+64 = 180

B = 180-64

B = 116

Then we can use the law of sines like so:

a/sin(A) = b/sin(B)

a/sin(38) = 10/sin(116)

a = sin(38)*10/sin(116)

a = 6.84986152123146

a = 6.8

Side 'a' is approximately 6.8 inches long. So that's why the answer is choice A.

If 4 cans of cat food costs $17.20, how many cans of cat food can be purchased
with $38.70

Answers

Answer:

9

Step-by-step explanation:

let the price of one can food be x,

4x=17.20

x=4.3

number of can foods that can be purchased = 38.70/x = 38.7/4.3 = 9

Step-by-step explanation:

4CANS=$17.20

$38.70

cross multiply

4 multiply by 38.70 =154.8 divide by 17.20

ANSWER = 9

Pls help no 6 i am giving a lot of points

Answers

Answer:

Use pythagoras theorem

Anyone Know The Answer???

Answers

Answer:

I think it is 2, downwards

Answer:

vertical shift of 2 units up

Step-by-step explanation:

Given f(x) then f(x) + c is a vertical translation of f(x)

• If c > 0 then a shift up of c units

• If c < 0 then a shift down of c units

f(x) = 9 | x + 1 | + 2

Represents a vertical shift of 2 units up of the parent function

In a circle with center P and radius 10cm. If one of the chord is of length 12 cm.

Then find the distance of the chord from the center.​

Answers

Look at the attachment

The line bisects the cord which we have to find

Length of chord=12cmHalf of the cord=12/2=6cmRadius=10cm

Its a right angle triangle

using Pythagorean theorem

[tex]\boxed{\sf P^2=H^2-B^2}[/tex]

[tex]\\ \Large\sf\longmapsto P=\sqrt{H^2-B^2}[/tex]

[tex]\\ \Large\sf\longmapsto P=\sqrt{10^2-6^2}[/tex]

[tex]\\ \Large\sf\longmapsto P=\sqrt{100-36}[/tex]

[tex]\\ \Large\sf\longmapsto P=\sqrt{64}[/tex]

[tex]\\ \Large\sf\longmapsto P=8cm[/tex]

Distance of the chord from centre is 8cm.

What is the sign of 3ay when 2 > 0 and y < 0?
Choose 1 answer
Positive
Negative
Zero

Answers

Option A - Positive Step-by-step explanation:
Given : Expression when
To find : What is the sign of the expression ?
Solution :
Expression
when
We know that,
When a negative unit is divided by a negative unit then the negative sign became positive sign as negative sign get cancel in numerator and denominator.

**25 POINTS**
Which of the following lists of ordered pairs is a function?

Answers

Answer: A

Step-by-step explanation: A function is when every domain (x value) corresponds to one range (y value) so that it passes the vertical line test

the product of 2x and 3 is 138. find the number x


Answers

Answer:

x = 23

General Formulas and Concepts:

Pre-Algebra

Equality Properties

Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtraction Property of Equality

Algebra I

Terms/Coefficients

Step-by-step explanation:

Step 1: Define

3(2x) = 138

Step 2: Solve for x

Simplify:                                                                                                             6x = 138[Division Property of Equality] Divide 6 on both sides:                                  x = 23

Please help!!! Much appreciated!!

Answers

Answer:

C

Step-by-step explanation:

As n → ∞

[tex]\frac{85}{n}[/tex] , [tex]\frac{75}{2n}[/tex] , [tex]\frac{15}{2n^2}[/tex] → 0

Then

15 - 35 - 0 + 55 + 0 + 0

= - 20 + 55

= 35 → C

The equation y=2(x-1)^2-5y=2(x−1)
2
−5y, equals, 2, left parenthesis, x, minus, 1, right parenthesis, squared, minus, 5 is graphed in the xyxyx, y-plane. Which of the following statements about the graph is true?

Answers

Answer:

(b) It is symmetrical about [tex]x = 1[/tex]

Step-by-step explanation:

Given

[tex]y = 2(x - 1)^2 - 5[/tex]

See attachment for options

Required

True statement about the graph

First, we check the line of symmetric

[tex]y = 2(x - 1)^2 - 5[/tex]

Expand

[tex]y = 2(x^2 - 2x + 1) - 5[/tex]

Open bracket

[tex]y = 2x^2 - 4x + 2 - 5[/tex]

[tex]y = 2x^2 - 4x -3[/tex]

A quadratic equation [tex]y = ax^2 + bx + c[/tex] has the following line of symmetry

[tex]x = -\frac{b}{2a}[/tex]

By comparison, the equation becomes:

[tex]x = -\frac{-4}{2*2}[/tex]

[tex]x = \frac{4}{4}[/tex]

[tex]x = 1[/tex]

Hence, the line of symmetry is at: [tex]x = 1[/tex]

(b) is true.

Answer: It is symmetrical about x=1

Step-by-step explanation:

Triangle Q R S is shown. Line R Q extends through point P. Angle Q S R is 35 degrees. Angle S R Q is 58 degrees. Exterior angle S Q P is x degrees. What is the value of x?

Answers

The triangle is missing and so i have attached it.

Answer:

x = 93°

Step-by-step explanation:

From the triangle attached, we can say that;

<SQP + <SQR = 180°

This is because sum of angles on a straight line equals 180°.

Secondly, we know that sum of angles in a triangle also equals 180°.

Thus;

<SQR + <QSR + <SRQ = 180

From the attached triangle, we see that;

<QSR = 35°

<SRQ = 58°

Thus;

<SQR + 35° + 58° = 180°

<SQR + 93° = 180°

<SQR = 180° - 93°

<SQR = 87°

From earlier on, we saw that;

<SQP + <SQR = 180°

Plugging in <SQR = 87°, we have;

<SQP + 87° = 180°

<SQP = 180° - 87°

<SQP = 93°

We are told in the question that <SQP is denoted by x.

Thus;

x = 93°

Answer:

The value of x is answer D: 93

calculate the amount of rupees 31250 at the end of 2½ years, compounded annually at 8% per annum.​

Answers

Principal = 31250

Time= 2 and 1/2 years

Rate= 8% so first we take out the amount for 2 years which would be: 36450

Now we we will take out the amount for 1/2 years. Now the rate for 1/2 years is 4% with principal

The amount for 1/2 years for 4% rate is= 37908

Answer: 37908 is the amount after 2 and 1/2 years at the rate of 8%

Reciprocal of 2 (1/7) is _​

Answers

Answer:

[tex]\frac{7}{15}[/tex]

Step-by-step explanation:

To find the reciprocal of a fraction, simply switch the numerator and denominator.

Since [tex]2\frac{1}{7}[/tex] is a mixed number, start by converting it to a common fraction using [tex]a\frac{b}{c}\implies \frac{a \cdot c+ b}{c}[/tex]

Therefore, [tex]2\frac{1}{7}[/tex] as a common fraction is:

[tex]\frac{2\cdot 7+1}{7}=\frac{14+1}{7}=\frac{15}{7}[/tex]

Now switch the numerator and denominator to find the reciprocal:

[tex]\rightarrow \boxed{\frac{7}{15}}[/tex]

Answer:

7/15

Step-by-step explanation:

2 1/7 is 2*7+1/7 = 15/7. The reciprocal of this would happen if you flip it upside down. Thus, the reciprocal is 7/15.

chứng minh đường thẳng a là tiếp tuyến của ( O,R) tại điểm C

Answers

omg what so true bestie

ever since Anthony started going to the gym 4 days per week he has been taking protein he wants to take every day to help build muscle. How many grams of protein does Anthony take for the entire day (100%)

Answers

Answer:

how much protein did he take per day tho?

The altitude a (in feet) of a plane t minutes after liftoff is given by a = 3400t + 600. How many minutes after liftoff is the plane at an altitude of 21,000 feet

Answers

Answer:

6

Step-by-step explanation:

Altitude = 3400t +600

21,000 = 3400t +600

21000-600= 3400t

20400/3400 = 3400t/3400

t= 6

Answered by Gauthmath

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