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Related Questions
A chemist examines 17 sedimentary samples for lead concentration. The mean lead concentration for the sample data is 0.268 cc/cubic meter with a standard deviation of 0.069. Determine the 80% confidence interval for the population mean lead concentration. Assume the population is approximately normal. Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.
Answers
Answer:
The critical value that should be used in constructing the confidence interval is T = 1.337.
The 80% confidence interval for the population mean lead concentration is between 0.246 and 0.29 cc/cubic meter.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 17 - 1 = 16
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 16 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.8}{2} = 0.9[/tex]. So we have T = 1.337, which is the crical value.
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 1.337\frac{0.069}{\sqrt{17}} = 0.022[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 0.268 - 0.022 = 0.246 cc/cubic meter
The upper end of the interval is the sample mean added to M. So it is 0.268 + 0.022 = 0.29 cc/cubic meter
The 80% confidence interval for the population mean lead concentration is between 0.246 and 0.29 cc/cubic meter
Part E Find half of the time that Devon skied without falling, and write inequalities to compare it with the times others in the family skied without falling.
Answers
Answer:
For Half of Devon's Time you would put 172 divide by 2 equals 186. For comparison:
kelvin 223>86
Lori 55<86
Vanessa 265>86
Celia 112>86
Arnold 356>86
Step-by-step explanation:
HELP ME PLEASE I DONT KNOW WHAT TO DO!!!!!!!!
Answers
Answer:
I would have to guess c because it show a decrease in the number line
Step-by-step explanation:
Step-by-step explanation:
ɪᴛs ᴛʜᴇ ʟᴀsᴛ ᴏᴘᴛɪᴏɴ D
ᴀs ᴛʜᴇ ᴅᴏᴛ ɪs ᴘᴏɪɴᴛᴇᴅ ʙᴇᴛᴡᴇᴇɴ -15 ᴀɴᴅ -20
A line has a slope of 5 and includes the points (1,t) and (3,2). What is the value of t?
Answers
Hello!
[tex]\large\boxed{t = -8}[/tex]
We can find the value of t using the slope formula:
[tex]slope = \frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]
Plug in the given slope and coordinates into the appropriate places:
[tex]5 = \frac{2-t}{3-1}[/tex]
Simplify:
[tex]5 = \frac{2-t}{2}[/tex]
Multiply both sides by 2 to begin isolating for t. Simplify and solve for t:
[tex]5 * 2 = 2 - t\\\\10 = 2 - t\\\\8 = -t\\\\t = 8[/tex]
When a card is selected from a deck, find the probability of getting a. A club b. A face card or a heart c. A 6 and a spade d. A king e. A red card
Answers
Answer:
Kindly check explanation
Step-by-step explanation:
Number of clubs = 13
Number of face cards = 12
Number of hearts = 13
Number of King's = 4
Number of reds = 26
Number of spade = 13
Number of 6's = 4
Total possible outcomes = total number of cards = 52
Probability = required outcome / Total possible outcomes
1.) P(A club) = 13 / 52
2.) P(face card or heart) =
p(face card) + p(heart)
12 / 52 + 13/52
= (12 + 13) / 52 = 25 /52
3.)
(A 6 and a spade)
4/52 * 13/52
= 52 / 2704
= 1/52
4.) A king
P(king) = 4 /52 = 1/13
5) A red
P(red) = 26 / 52 = 1/2
Work out
139% of 722.71kg
Give your answer rounded to 2 DP.
Answers
u simplify 722.71 and 100 and see the common multiples-
and if you do normal multiplication or division , u can use calculator btw but the answer is 1004.5669
According to Inc, 79% of job seekers used social media in their job search in 2018. Many believe this number is inflated by the proportion of 22- to 30-year-old job seekers who use social media in their job search. Suppose a survey of 22- to 30-year-old job seekers showed that 308 of the 370 respondents use social media in their job search. In addition, 281 of the 370 respondents indicated they have electronically submitted a resume to an employer.
A) Conduct a hypothesis test to determine if the results of the survey justify concluding the proportion of 22- to 30-year-old job seekers who use social media in their job search exceeds the proportion of the population that use social media in their job search. Use α = 0.05.
1) State the null and alternative hypothesis.
2) Find the value of the test statistic.
3) Find the p-value.
B) Conduct a hypothesis test to determine if the results of the survey justify concluding that more than 70% of 22- to 30-year-old job seekers have electronically submitted a resume to an employer. Using α = 0.05, what is your conclusion?
1) State the null and alternative hypothesis.
2) Find the value of the test statistic.
3) Find the p-value.
Answers
Answer:
A) i) Null hypothesis; p ≤ 0.79
Alternative hypothesis; p > 0.79
ii) test statistic = 2
iii) P-value = 0.02275
B) i) Null hypothesis; p ≤ 0.70
Alternative hypothesis; p > 0.70
ii) test statistic = 2.5
iii) P-value = 0.00621
Step-by-step explanation:
A) We are given;
Population proportion; p = 79% = 0.79
308 of the 370 respondents use social media in their job search. Thus;
Sample proportion; p^ = 308/370 = 0.8324
Let's state the hypotheses;
Null hypothesis; p ≤ 0.79
Alternative hypothesis; p > 0.79
Formula for the test statistic is;
z = (p^ - p)/√(p(1 - p)/n)
z = (0.8324 - 0.79)/√(0.79(1 - 0.79)/370)
z = 0.0424/0.021175
z = 2
From online p-value from z-score calculator attached and using; z = 2; significance value = 0.05; and one tailed distribution, we have;
P-value = 0.02275
B) similar to answer A above, Population proportion; p = 70% = 0.70
But 281 of the 370 respondents use social media in their job search. Thus;
Null hypothesis; p ≤ 0.70
Alternative hypothesis; p > 0.70
Also; Sample proportion; p^ = 281/370 = 0.7595
Formula for the test statistic is;
z = (p^ - p)/√(p(1 - p)/n)
z = (0.7595 - 0.70)/√(0.70(1 - 0.70)/370)
z = 0.0595/0.023824
z = 2.5
From online p-value from z-score calculator attached and using; z = 2.5; significance value = 0.05; and one tailed distribution, we have;
P-value = 0.00621
A test has 20 questions. If Peter gets 80% correct, how many questions did Peter miss?
Answers
Answer:
4
Step-by-step explanation:
20 x 0.80
16 - 20
Answer:
4 questions
Step-by-step explanation:
4 wrong = 80%
can you answer this
Answers
Answer:
B. 7ab²c
Step-by-step explanation:
The GCF of 21a²b^4c and 49ab²c³ is
7ab²c
Answer:
The correct answer is b.
solve using any method 4x-y=20 and -2x-2y=10
Answers
Answer:
if you're trying to find the slope, it is (3, -8) were you looking for the slope?
Step-by-step explanation:
i hope this helps, have a great day:)
Answer: the answer is x =3, y = -8
Step-by-step explanation:
Among all pairs of numbers whose sum is 6, find a pair whose product is as large as possible.
What is the maximum product?
Answers
Step-by-step explanation:
The pairs of numbers whose sum is 6 starting from zero is ;
0,6
1,5
2,4
3,3
Kindly note 2,4 is same as 4,2 , so there is no need for repetition
So the maximum product is 3 * 3 = 9 and the pair is 3,3
Answer:
The pair of numbers is (3,3) while the maximum product is 9
Step-by-step explanation:
The pairs of numbers whose sum is 6 starting from zero is ;
0,6
1,5
2,4
3,3
Kindly note 2,4 is same as 4,2 , so there is no need for repetition
So the maximum product is 3 * 3 = 9 and the pair is 3,3
Step-by-step explanation:
hope this helps :)
A store sells 8 small, 18 medium, and 20 large sweatshirts. Each sweatshirt costs $16. How much money, m, is the store paid for all the sweatshirts they sell?
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Answer:
8+18+20x16 ,
Step-by-step explanation: yeah .
You treat your friend to lunch. The food bill was $30.24. A 7% sales tax will be added and you want to leave a 20% tip.
a. Find the sales tax.
b. Find the tip.
c. Find the total amount you pay for lunch.
Answers
Answer:
a. $2.12
b. $6.45
c. $38.81
Step-by-step explanation:
a.
I'll convert 30.24 and 7% into fractions.
756/25 * 7/100
Cross cancel 756 and 100 (GCF is 4)
189/25 * 7/25
Convert above into a single fraction
(189 * 7)/(25 * 25)
Multiply 189 by 7, then 25 by 25.
1323/625
Divide, then round to the nearest cent
$2.1168 ≈ $2.12 in sales tax
b.
Like before, I'll convert $32.26 ($30.24 + $2.12) and 20% into fractions.
1613/50 * 1/5
Multiply 50 by 5.
1613/250
Divide, then round to the nearest cent.
$6.452 ≈ $6.45 in tip money
c.
This is probably the simplest part of the 3. Just add $30.24 + $2.12 + $6.45.
$30.24 + $2.12 + $6.45
$32.36 + $6.45
You pay a total of $38.81 for lunch.
how many miles per hour does it take to go 160 miles in 4.5 hours
Answers
What is - 0.9 as a decimal
Answers
Answer: -0.9 as a decimal is -0.9
but if you meant as a fraction, then it's -9/10
Step-by-step explanation:
Answer:
0.9
Step-by-step explanation:
There Are Several Ways To Write 0.9.
1) 0.9
2)0.90
3)9/10
4)90/100
Hope this was able to help you!
-TheAnimeCatUwU
#LearnWithBrainly
I need help with this can someone help
Answers
My work:
3x4=12
12+12=24
6-4=2
2+2+2=6
24÷6=4
Your answer:
4
Hope this helps!
-Alex
Answer:
18.
Step-by-step explanation:
3 x 4 = 12, 12 times 12 equals 144, 6 - 4 equals 2, and 2 times 2 times 2 is 8, and 144 / 8 = 18.
Mr. Alpert’s house has 40 windows. Kids playing baseball outside the house broke 10% of the windows.
Answers
Answer:
Step-by-step explanation:
Number of windows broken = 10% of 40
[tex]= \frac{10}{100}*40\\= 4[/tex]
Answer:
4 windows are broken
Step-by-step explanation:
Simplify (4+y) + (8y - 5)
Answers
Answer:
it is 9y-1
Step-by-step explanation:
You have to simplify the expressions.
Mrs. Diaz has 4 brownies left. She wants to share the brownies equally among her 5 children Which of the following shows the amount of brownies each child can receive?
Answers
Step-by-step explanation: I had that q and got it right
UwU
PLEASE HELP!!!
question 1: What is the coefficient of the third term of the trinomial? (In other words, what is C?)
(2x + 3)(4x − 1) = 8x^2 +10x − C
Question 2: What is the coefficient of the second term of the polynomial? (In other words, what is B?)
(x + 2)(2x^2 + x − 1) = 2x^3 + Bx^2 + x − 2
question 3: What is the coefficient of the third term of the polynomial? (In other words, what is C?)
(x + 2)(x^2 −3x − 2) = x^3 −x^2 −Cx − 4
Answers
The value of C is -3 and the value of B is 5
ExpansionGiven the expression
(2x + 3)(4x − 1)
On expansion, ww will have:
(2x + 3)(4x − 1) = 8x^2 - 2x + 12x - 3
(2x + 3)(4x − 1) = 8x^2 + 10x - 3
Hence the value of C is -3
For the expression (x + 2)(2x^2 + x − 1)
Expnd
(x + 2)(2x^2 + x − 1) = 2x^3 + x^2 - x + 4x^2 + 2x - 2
(x + 2)(2x^2 + x − 1) = 2x^3+ 5x^2 +x - 2
Hence the value of B is 5
Learn more on expansion here: https://brainly.com/question/13602562
Chris works at a jewelry store, and he earns 4% commission on all sales that he makes. If Chris's jewelry sales total $1,370, how much will he earn in commission?
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A cylinder with radius 7 centimeters and height 9 centimeters has its radius quadrupled. How many times greater is the volume of the larger cylinder than the smaller cylinder .
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Answer:
16 times larger
Step-by-step explanation:
f(x) = x^2. What is g(x)?
Answers
g(x)= 3x^2
ignore this:isnsjsbjs sjsdjsnsnssnsnnsnsns
Answers
Answer:
4
Step-by-step explanation:
i dont wanna explain but the answer is 4
I TYPED IN THE ANSWER CAN SOMEONE CORRECT IF IT IS WRONG?
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Answer: No you are not wrong
Step-by-step explanation:
find the area of the shaded region under the
standard normal curve. If convenient, use technology to find the area
Answers
Answer
The area of the shaded region under the standard normal curve is 0.4834.
Step-by-step explanation:
A random variable X is said to have a normal distribution with mean, µ and variance σ².
Then , is a standard normal variate with mean, E (Z) = 0 and Var (Z) = 1. That is, Z N (0, 1).
The distribution of these z-variates is known as the standard normal distribution.
Compute the area under the curve between -2.13 and 0 as follows:
Thus, the area of the shaded region under the standard normal curve is 0.4834.
Gabin takes care of the management of the electricity department of a DIY store. He contacts his wholesaler for an order of electrical products. The wholesaler tells him that the net purchase price will be E7,825, to which must be added a purchase charge of E 325 1. Indicate how to obtain the purchase cost. 2. Calculate the cost of purchasing electrical products.
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Answer:
I have no clue.,...
.....
pls help me on this.......
Answers
Hey there!
Your answer is [tex]-4x+7[/tex]
Here are the steps to solve:
Given:
[tex]-5x-(x-7)[/tex]
Distribute negative sign:
[tex]-5x+x+7[/tex]
Add like terms:
[tex]-4x+7[/tex]
Have a great day! Hope it helped!
help pls i'll give brainliest, are they inverses or not explain why or why not
Answers
Solve 3(x + 1) = −2(x − 1) − 4
-1
1
-3
5
Answers
Answer:
x = -1
Step-by-step explanation:
3(x + 1) = -2(x - 1 ) - 4
use the distributive property to get rid of the parentheses. on -2 and -1 they cancel each other out so it becomes + 2. now you have:
3x + 3 = -2x + 2 - 4 (+2 and -4 are like terms so they become -2. so technically its 3x + 3 = -2x -2)
get +3 on the other side by subtracting it from itself and then subtracting it from -2 so it becomes -5.
3x = -2x - 5
get -2x on the other side by adding 2x to itself then adding 2x to 3x so it becomes 5x
5x = -5
divide 5 from -5 and you get x = -1