A researcher wants to estimate the mean commute time of residents in Westchester County. The researcher samples 40 commuters and find the mean commute time to be 25 minutes. Assume the population standard deviation for commute time is 12.5 minutes. Construct a 90% confidence interval for the mean commute time of residents in Westchester County. What is the Lower Bound of the confidence interval

Answers

Answer 1

Answer:

21.759

Step-by-step explanation:

Given that :

Mean (m) = 25

Standard deviation (s) = 12.5

Sample size (n) = 40

α = 90%

The confidence interval is obtained using the relation:

Mean ± Zcritical * s/sqrt(n)

Zcritical at 90% confidence interval = 1.64

25 ± 1.64 * (12.5/sqrt(40))

Lower boundary : 25 - 1.64(1.9764235) = 21.75866546

Upper boundary : 25 + 1.64(1.9764235) = 28.24133454

(21.759, 28.241)

Hence, lower bound of confidence interval is : 21.759


Related Questions

–sin2(x) = cos(2x) from [–π,π]

I need help on this

Answers

If the equation is

- sin²(x) = cos(2x)

rewrite the left side using the Pythagorean identity,

sin²(x) = 1 - cos²(x)

and the right side using the double angle identity for cosine,

cos(2x) = 2 cos²(x) - 1

Then the equation transforms to

- (1 - cos²(x)) = 2 cos²(x) - 1

Solve for cos²(x) :

-1 + cos²(x) = 2 cos²(x) - 1

cos²(x) = 0

Take the square root of both sides to get

cos(x) = 0

Solve for x :

x = cos⁻¹(0) + 2   or   x = cos⁻¹(0) - π + 2

x = π/2 + 2   or   x = -π/2 + 2

where n is any integer. We get solutions in the interval [-π, π] when n = 0, giving the solutions

x = π/2   or   x = -π/2

ray bd bisects angle abc. solve for x

Answers

Answer:

x = 10

Step-by-step explanation:

Since, ray BD bisects ∠ABC,

Therefore, m∠ABD = m∠CBD

By substituting the values of the angles,

x° = (4x - 30)°

x - 4x = -30

-3x = -30

x = 10

Therefore, x = 10 will be the answer.

QUICK I GOT 2 MINUTES
We had dinner at Joe's Crab Sahck. The bill was $200. We had a coupon for 15% discount. We decided to pay the waitress 20% tip and a 7% tax. What was the amount of final bill?

Answers

Answer:

I think it is 224.

Other:

Brainliest? Thanks!

x =0, y>=0 Maximum for P =3x +2y

Answers

Answer:

day

Step-by-step explanation:

6th grade and the final grade for this semester and the

Is this a function?

Answers

Answer:

It isn't a function.

Step-by-step explanation:

Since there are two points on the same x value, in this case x=3, this means that these points can not be a function.

What is 40% of 25 is it
A. 62.50%
B. 16%
C. 160%
D. 10%

Answers

40 percent of 25 is D. 10%

Step-by-step explanation:

D. 10 %

hope it helps!

.......

A USB stick can store 1.1x10 power of 3
megabytes of data.
A hard drive can store 4x10 power of 4
megabytes of data.
How much more can the hard drive store?
Give your answer in standard form

Answers

Answer:

uhhh

Step-by-step explanation:

Answer:

3.82 x 10

Step-by-step explanation:

divide 4 x 10^4 by 1.1 x 10^3

4 divided by 1.1 is 3.81818181... and you subtract exponents to get 1

find the angle measure of minor arc MP.

Answers

Step-by-step explanation:

Angle at center = 2 * Angle at circumference.

Angle MNP = 2 * Angle MQP = 30°.

Hence the angle measure of minor arc MP is 30°.

Answer:

30 degrees

Step-by-step explanation:

arc measure in degrees is twice the measure of the inscribed angle

Ariane borrows $200 on a 2−year loan. She is charged 5% simple interest per year. How much interest is she charged for 2 years? What is the total amount she has to pay back?

Answers

Answer:

Interest charged over two years: $20

Total amount: $220

Step-by-step explanation:

The formula for simple interest is A = P ( 1 + rt ).

A = 200 ( 1 + (0.05 * 2))

A is the total amount ( interest + principle )

A = 220

P is the principle ( initial amount deposited )

P = 200

R refers to rate (in percent)

R = 0.05

T = time period (in years)

T = 2

Which situation represents a non-proportional relationship?



The cost of purchasing p pounds of salmon for $7.99 per pound.

The amount a student makes mowing m number of lawns charging $35 per lawn.

The amount of water draining at a rate of 2.5 gallons per minute.

The total cost of renting a jet ski for $25 per hour plus a fee of $50.

Answers

Answer:

Correct option:

"The total cost of renting a jet ski for $25 per hour plus a fee of $50."

Step-by-step explanation:

Proportional relationships are associations between two variables where the ratio of these two variables are correspondent. Or, in a proportional relationship, one variable is a constant value times the other variable. This constant is known as the "constant of proportionality".

The first three options represents a proportional relationship.

But the last option does not.

"The total cost of renting a jet ski for $25 per hour plus a fee of $50."

That is,

TC = 25·h + 50

The relationship is linear not proportional.


A team won 13 games, lost 15 games, and tied 2
games. What percent of its games did the team win? I need help please!!

Answers

Answer:

43%

Step-by-step explanation:

First, find the total amount of games:

13 + 15 + 2

= 30

Then, to find the percentage of games won, divide 13 by 30:

13/30

= 0.43

So, the team won approximately 43% of its games

Answer: Approximately 43.3%

Work Shown:

13+15+2 = 30 games total

Divide the number of games won (13) over the number total (30)

13/30 = 0.433 approximately which converts to 43.3% of the games won

To convert from decimal form to percent form, move the decimal point over to the right two spaces. Another example would be 0.83 converts to 83%

Hamburger meat cost $3.68 pound. which equation best represent y, the total cost of x pounds of hamburger meat?

Answers

Answer:

Y=3.68x

Step-by-step explanation:

Answer:

Its should be y=$3.68(X)

I need the answer ASAP

Answers

Answer:

the are is 14

brainliest??

Step-by-step explanation:

Answer:

48ft

Step-by-step explanation:

Hope this helps. :)

I WILL GIVE BRAINLIST Answer the questions to compare 3/12 and 2/9 by using their decimal forms.

1. How can you find the decimal forms of 3/12 and 2/9?

2. Find the decimal form of 3/12 Show your work


3. Find the decimal form of 2/9 Show your work

Answers

Answer:

3/12=0.25

Step-by-step explanation:

3/12=1/4

1/4*25/25 =25/100

25/100 = 0.25

Answer:

1.  To find the decimal form of 2/9 and 3/12, you have to divide the numerator by the denominator.

2. 0.25

3. 0.22222222

Step-by-step explanation:

1. pretty much explained it

2. divided the numerator by the denominator

3. same thing as 2 (divided the numerator by the denominator)

Of the
44
people who started a math class meeting at
10
:
00
each morning, only
37
finished the class. What fraction of people finished the class?

Answers

Answer: .8409 or 37/44

Step-by-step explanation:

A triangle has side lengths of 13 feet, 18 feet, and 12 feet. What kind of triangle is it?

Answers

this is a scalene triangle

Answer:

Scalene Triangle

Step-by-step explanation:

A scalene triangle is a triangle that’s supposed to have all three sides with unequal lengths.

Which function could be represented by the graph on the
coordinate plane?

Answers

The last option f(x)=(x-8)^2 -6

The reason is that whatever is in the parenthesis is always opposite. So since the graph is on the right side that means it’s -8 not positive 8. And the -6 represents a vertical translation and the graph is placed below zero.

Answer:

f(x)=(x-8)^2 -6

Step-by-step explanation:

Mike has a collection of baseball cards and baseball figurines. If the ratio of cards to figurines is 5:7 and there are 25 cards in his collection, how many figurines does he have

Answers

Answer:

35 figurines

Step-by-step explanation:

if the ratio of cards to figurines is 5:7 and there are 25 cards, we multiply the ratio by 5 to make the 5 into a 25 and so can find out how mant figurines there are.

5*5:7*5= 25:35

so there are 35 figurines

help me ples 20 point

Answers

Answer:

40%

Step-by-step explanation:

6/15 * 100 = 0.4 * 100 = 40%

Answer:

40% of the pieces of fruit in the Bowl are apples.    

Step-by-step explanation:

Given the statement:- There are 15 pieces of fruit in a bowl and six of them are apples.

Total number of pieces of fruit  in a bowl = 15 pieces

Number of pieces of apple in a bowl = 6 pieces.

Therefore, 40% of the pieces of fruit in the Bowl are apples.

MULTIPLE CHOICE QUESTION
What is the COP of the table below?
X
Y
2
1
4.
2
6
3
8
4
K = 2/4
K = 4/2
K = 1/2
K = 2/1

Answers

Answer:

K = 2/1

Step-by-step explanation:

Constant of proportionality can be found using any two given pair of values.

Constant of proportionality = y/x

Therefore, using (1, 2) , we have

Constant of proportionality = y/x = 2/1 = 2

Or it can be written as: k = ²/1 = 2

Which relationship between x and y in the equation shows a proportional relationship?
y=3x
y=5(r+3)
y=x-2
y=5x +3

Answers

Answer:

Y=3x

Step-by-step explanation:

Proportional relationships always have multiplication or division

−4(m+3)=24
m=?
If you know the answer, please let me know. I really need help. Thank you.
(If the answer is right, this person will be the smartest)

Answers

Answer:

Your answer is going to be m=-9

Step-by-step explanation:

(-4(m+3))/-4=(24)/-4

m+3=-6

   -3  -3

m=-9

Evaluate x² + 2x - 4 if x = -4.

Answers

Answer:

the answer is ;4

Step-by-step explanation:

What is .63 converted into a decimal?

Answers

Answer: 63 as a decimal is 0.63

Step-by-step explanation:

Answer:

the answer to your question is 0.63

f(x) = 4x4-3x3–2x2-5 possible zeros

Answers

Answer:

f(x)= 1 correct me if wrong :)

Step-by-step explanation:

4 times 4 is 18

3 times 3 is 9

18-9=8

2 times 2 is 4

8-4=4

4-5=1

i need a step by step explanation

Answers

Answer:

1/2c-4

Step-by-step explanation:

First, you distribute the fraction on the outside to the numbers inside of the parenthesis. So, you distribute 1/2 to c, which gives you 1/2 x c = 1/2c. Then, you distribute the 1/2 to -8, which gives you 1/2 x -8 = -4. You combine these expression together and get your final answer as 1/2c-4.

How is the space between consecutive whole numbers divided on the number line?
O into halves
O into fifths
O into sixths
O into sevenths

Answers

Answer:

I think it’s is into fifths if I’m correct

Step-by-step explanation:

Mr. and Mrs. Brown went to two movies. The first one lasted 3 1/2 hours and the second one lasted 1 1/3 hours . How much longer was the first than the second movie?

Answers

Answer:

2 1/6 longer

Step-by-step explanation:

3 1/2-1 1/3

7/2 - 4/3

21/6-8/6

13/6 or 2 1/6

so 2 1/6 longer.

Hope this helps :D

Answer:

2 1/6 hours longer

Step-by-step explanation:

Hope the helps!

Note: Enter your answer and show all the steps that you use to solve this problem in the space provided.

Solve.

4x + 6 < -6

plz show ur work ♡​

Answers

Answer:

The answer is x<−3

Step-by-step explanation:

Step 1: Subtract 6 from both sides.

4x+6−6<−6−6

4x<−12

Step 2: Divide both sides by 4.

[tex]\frac{4x}{4} =\frac{-12}{4}[/tex]

x<−3

Figure AAA is a scale image of Figure BBB.

Answers

Answer:

that hard than i though

Step-by-step explanation:

Answer:

x=12

Step-by-step explanation:

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