In a random sample of 8 people, the mean commute time to work was 35.5 minutes and the standard deviation was 7.4 minutes. A 90% confidence interval using the t-distribution was calculated to be (30.5,40.5). After researching commute times to work, it was found that the population standard deviation is 9.3 minutes. Find the margin of error and construct a 90% confidence interval using the standard normal distribution with the appropriate calculations for a standard deviation that is known. Compare the results.
Answer:
Margin of Error = 5.4088 ;
Confidence interval = (30.1 ; 40.9)
Interval estimate are almost the same
Step-by-step explanation:
Given that :
Population standard deviation, σ = 9.3
Sample size, n = 8
Xbar = 35.5
Confidence level = 90%
The confidence interval:
Xbar ± Margin of error
Margin of Error = Zcritical * σ/sqrt(n)
Zcritical at 90% = 1.645
Margin of Error = 1.645 * 9.3/sqrt(8) = 5.4088
Confidence interval :
Xbar ± Margin of error
35.5 ± 5.4088
Lower boundary = (35.5 - 5.4088) = 30.0912 = 30.1
Upper boundary = (35.5 + 5.4088) = 40.9088 = 40.9
(30.1 ; 40.9)
T distribution =. (30.5 ; 40.5)
Normal distribution = (30.1, 40.9)
Which of the expressions are equivalent to the one below? Check all that
apply.
10x(3+4)
A. (3+4)x10
O B. (10x3) + 4
C. 10.3 + 10 - 4
D. 10. (4+3)
SUBMIT
Please help
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Thanks besties
Answer:
62.33 degrees Fahrenheit.
Anytime bestie <3
Patrick has an art supplies box with colored pencils and markers. The ratio of colored pencils to markers is 7:4. If Patrick has 63 colored pencils in the box, how many markers does he have.
Please help me if you can!
please help !
Find the value of x. Round to the
nearest tenth.
26°
12
X
x = [?]
Answer:
x = 5.85
Step-by-step explanation:
Given that,
One angle = 26°
Middle angle = 90°
Third angle = 180-(90+26) = 64°
Height, H = 12
We need to find the value of x. Using trigonometry to find it such that,
[tex]\tan64=\dfrac{12}{x}\\\\x=\dfrac{12}{\tan(64)}\\\\x=5.85[/tex]
So, the value of x is equal to 5.85.
Answer:
5.9
Step-by-step explanation:
im doing this rn
Please help marking brainliest
Answer: The length of each side of the tiles is 7.2 in
Step-by-step explanation:
how do you add an equation vertically
"Vertically" probably refers to stacking the polynomials on top of each other and aligning them at equal powers of x. So kind of like what you might do when adding two numbers with more than 1 digit each.
For example, the sum 123 + 456 can be computed by adding digits in the same digits place:
… 1 2 3
+ 4 5 6
… 5 7 9
Then for this sum, you have
… - 3x ² - 6x + 8
+ 8x ² + 7x - 14
… 5x ² + x - 6
Find the surface area of the cylinder. Round your answer to the nearest tenth.
IF YOU ANSWER THE QUESTION CORRECTLY I WILL GIVE YOU BRAINIEST.
Answer:
188.5ft²
Step-by-step explanation:
Surface area of cylinder = 2πrh+2πr²
=2π3*7+2π3²
=42π+18π
=60π=188.495559215≈188.5ft²
Which triangles are right triangles?
Select ALL correct answers.
Answer:
2 , 3 ,4
Step-by-step explanation:
to find the right triangle use the pythagorian method
A^2+B^2= C^2
In a poll, a random sample of 2163 adults (aged 18 and over) was asked, "When you see an ad emphasizing that a product is made in your country, are you more likely to buy it, less likely to buy it, ar neither more nor less likely to
buy it? The results of the survey are presented in the side by side graph. Complete parts (a) through (d) below
Leihood to Buy When Made in Home Country
More
Les likely
| Neither
02
(a) What proportion of 18 to 34 year-old respondents are more likely to buy when made in their country? What proportion of 35 to 44 year-old respondents are more likely to buy when made in their country?
Answer:
Step-by-step explanation:
(a) What proportion of 18- to 34-year-old respondents are more likely to buy when made in their country? What proportion of 35- to 44-year-old respondents are more likely to buy when made in their country?
The proportion of 18- to 34-year-old respondents is
0.66
The proportion of 35- to 44-year-old respondents is
0.56
(b) What age group has the greatest proportion who are more likely to buy when made in their country?
18-34 yrs
(c) Which age group has a majority of respondents who are less likely to buy when made in their country?
55+
(d) What is the apparent association between age and likelihood to buy when made in their country?
As age decreases, the likelihood to buy homegrown increases
I BEG FOR MY LIFE EZ PLS
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Answer:
Step-by-step explanation:
Answer:
B and D
Step-by-step explanation:
The volume of a rectangular prism is found by multiplying the base, height and depth. So, to find the correct answer, multiply each and see which are equal to 72:
A) 7*3*5 = 105
B) 8*9*1 = 72
C) 3*8*4 = 96
D) 12*3*2 = 72
E) 3*4*5 = 60
Since B and D are the only ones that equal 72, they are the possible answers to give a volume of 72 units cubed.
Find the measure of each angle
Answer:
angle O = 36 degrees
angle N = 54 degrees
Step-by-step explanation:
90 degrees = angle O and N
2a + 18 + 5a + 9 = 90
7a + 27 = 90
7a = 63
a = 9
2(9) + 18 = 36 degrees
5(9) + 9 = 54 degrees
find the Range 11,10,15,17,14
(highest) -(lowest)
17-10
=7
What is the area of the figure?
A.)24 square inches
B.)28 square inches
C.)45 square inches
D.)55 square inches
Answer:
24 square inches
Step-by-step explanation:
Based on the diagram or figure given, The area of the figure is known to be 24 square inches.
What is the area of a figure?The area of a figure is known to be the rate or the number of unit squares that is said to have cover the surface of a closed figure.
Note that the area is often measured in square units such as (cm²) and in the case above, the Based on the diagram or figure given, The area of the figure is known to be 24 square inches.
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PLEASE HELPPP WITH THIS
Answer:
8 or D
Step-by-step explanation:
I say this because AD is 8 so im thinking it should be parallel and so the same would be for the opposite, AE.
Please solve this problem
The manager of the customer service department of an e-commerce company wants to know the average hold time for customers who call the department. The department receives about 850 calls each hour. The following data set shows the hold time, in minutes, for 10 calls picked at random. 2,1,4,5,3,3,7,4,3,2. Calculate the approximate hold time for all customers who call the customer service department.
The approximate hold time for all customers who call the customer service department is A 4 minutes. B 3 minutes. cannot be calculated from the given data. d 7 minutes
Answer:
The answer is approximately 3.
Step-by-step explanation:
You add all the numbers and then divide by 10
The approximate hold time for all customers who call the customer service department is 3 minutes.
What is a mean?Mean is the average of the given numbers and is calculated by dividing the sum of given numbers by the total number of numbers.
For the given situation,
The department receives about 850 calls each hour.
The data set shows the hold time, in minutes, for 10 calls picked at random. 2,1,4,5,3,3,7,4,3,2.
The approximate hold time for all customers who call the customer service department is calculated by mean as
⇒ [tex]\frac{sum of number of data sets}{Total number of data sets}[/tex]
⇒ [tex]\frac{2+1+4+5+3+3+7+4+3+2}{10}[/tex]
⇒ [tex]\frac{34}{10}[/tex]
⇒ [tex]3.4[/tex] ≈ [tex]3[/tex]
Hence we can conclude that the approximate hold time for all customers who call the customer service department is 3 minutes.
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Collin bought one T-shirt for $7.90 and another T-shirt for $12.40. What is the total amount he spent?
Will someone please please help me
Answer:
Step-by-step explanation:
12 + 5 = 17
square root of 9 = 3
5 x 4 = 20
bathroom that is 6 feet long. If the mirror sells for $4.00 per square foot, what will the total cost of the mirror be?
the equation is
Y=4x + 2
-6x+ 2y=8
I'm trying to figure out whats the value of x +y
Answer:
Y = 4x +2
substitute Y into the second equation
-6x +2[4x +2] =8
-6x +8x +4 =8
collect like terms
-6x +8x =8-4
2x=4
x=2
Substitute (x=2) into the first equation
Y= 4(2) +2
Y= 8+2
Y= 10
Responda: Por favor, é urgente.
Answer:
C) CA=40
Step-by-step explanation:
2y/(2y+4)=(2y+6)/4y
cross multiply
8y²=4y²+20y+24
4(2y²)=4(y²+5y+6)
divide both sides by 4
2y²=y²+5y+6
y²-5y-6=0
(y-6)(y+1)=0
So the answer must be either 6 or -1. Since it can't be a negative number, it must be 6.
CA=2(6)+4+4(6)
CA=12+4+24
CA=40
A retiree invests $7,000 in a savings plan that pays 7% per year. What will the account balance be at
the end of the first year?
Answer:
$6510
Step-by-step explanation:
First thing that should come to mind is: What is 7% of $7000?
Well, if you don't know how to find a percent of something, this is the formula you use:
7000 x 0.07 = 490.
In the first year, they will receive 490 out of the 7000 they've invested.
7000 - 490 = 6510.
Therefore, the account balance at the end of the first year will be 6510.
The account balance at the end of first year will be equal to $6510.
What do you mean by percentage ?
Percentage is the relative value indicating one hundredth part of any quantity.
It is given that a retiree invests $7000 in a savings plan which pays 7% per year. So , it meant that we need to calculate that what is the value 7% of $7000.
So , 7% of $7000 is :
= 7000 × [tex]\frac{7}{100}[/tex]
= $490
It is known that this amount is paid as per plan per year. So, to find out the account balance at the end of the first year , we need to subtract the invested amount to the amount per year at 7%.
So , the account balance at the end of first year will be :
= 7000 - 490
= $6510
Therefore , the account balance at the end of first year will be equal to $6510.
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HOW LONG IS PQ?
special right triangles khan academy
Answer:
Step-by-step explanation:
The side opposite to the angle 30 degree in right triangle is half of hypothenuse.
help me please!!!
solve a quadratic equation by factoring
solve for g.
g^2-24g+144=0
9514 1404 393
Answer:
g = 12
Step-by-step explanation:
You recognize that 144 is 12², so you check to see if the x-coefficient is 2·12. It is. The quadratic is a square:
(g -12)² = 0
The only solution is the one that makes the squared term equal to zero:
g -12 = 0
g = 12
_____
The square of a binomial is ...
(a +b)² = a² +2ab +b²
Here, we have a=x, b=-12.
Which graph shows the solution to the following system of inequalities?
{x - y = 1
y - x = 1
The lines are parallel.
The lines are coinciding.
The lines intersect at (1, 0).
The lines intersect at (–1, 0).
The can show below is a cylinder made of aluminum. The diameter of the can is 3 inches and the height of the can is 4 inches.
Which is closest to the total surface area of the can?
A. 14 in
B. 38 in.
C. 28 in.
D.52 in.
Whats the answer for 7/9 - 4/9 in fraction in number
Answer:
3/9
Step-by-step explanation:
numerator:7-4=3/9
The subtraction of the the fraction 7/9 -4/6 results to 1/3.
Given Fraction:
7/9 - 4/9
To subtract fractions, have a common denominator.
In this case, both fractions already have the same denominator of 9,
Now, subtract the numerators as:
= 7/9 - 4/9
= (7 - 4)/9
= 3/9
By dividing both the numerator and denominator by 3 gives
3/9 = 1/3
So, the answer to 7/9 - 4/9 as a simplified fraction is 1/3.
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hey guys help pls!!!
Answer:
B
Step-by-step explanation:
I drew it out and triangle b is correct