A paint manufacturer wants to determine the average drying time of a new interior wall paint. For n = 50 test areas of equal size he obtained a sample mean drying time of ¯x = 63.3 minutes and a sample standard deviation of s = 8.4 minutes. (a) (5 points) Construct the 95% confidence interval for the true mean µ. (b) (5 points) Suppose the population has a normal distribution, construct the exactly 95% confidence interval for the true mean µ. (c) (5 points) Suppose the population has a normal distribution, construct the 95% prediction interval for a new observation.
Answer:
a) the 95% confidence interval for the true mean µ is 60.971, 65.629
The exact 95% confidence interval for the true mean µ is 60.971, 65.629
P (x`- ∝ s/√n<u <x`+ ∝ s/√n) = 0.95
Step-by-step explanation:
n= 50
x`= 63.3
s= 8.4 minutes
∝= 95%= ±1.96
The formula for calculating the confidence interval is:
x`± ∝ s/√n
Putting the values
x`± 1.96 s/√n
63.3 ± 1.96(8.4/√50)
63.3± 2.3287
60.971, 65.629
a) the 95% confidence interval for the true mean µ is 60.971, 65.629
b) Putting the values
x`± 1.96 s/√n
63.3 ± 1.96(8.4/√50)
63.3± 2.3287
The exact 95% confidence interval for the true mean µ is 60.971, 65.629
c) The prediction level tells that the drying time of the wall from 60.971 to 65.629 minutes must be in the range 95 % of the time.
And is given by
P (x`- ∝ s/√n<u <x`+ ∝ s/√n) = 0.95
How much 9% saline solution should be mixed with 80 Cc of a 17% saline solution to produce a 13% saline solution?
Answer:
80 cc.
Step-by-step explanation:
We work in amounts of salt in the solutions:
0.09x + 0.17*80= 0.13(x+ 80) where x is the required volume of 9% solution.
0.09x + 13.6 = 0.13x + 10.4
13.6 - 10.4 = 0.13x - 0.09x
3.2 = 0.04x
x = 3.2 / 0.04
x = 80
Round the fraction to 0, 1/2, or 1.
2/9
PLEASE HELPPP!!! Use the image to help u out
Answer:
Nope
Step-by-step explanation:
Linear equation : Y = Mx + C
gradient = M
Y-intercept = C
To find gradient : (y1 - y2) / (x1 - x2):
(20 - (-25)) / (-4 - 11)
45 / -15 = -3
The given gradient is however 1/3. So The given equation is wrong
Which is the sum of and 3/10 and 1/3
Step-by-step explanation:
sum=addition
3/10 +1/3
find the LCM of 10 and 3 Which is 30
9+10/30=19/30
I hope it helps ☺️
Find the area of the figure shown below and chose the appropriate result
Answer:
it's the first option or A
Step-by-step explanation:
well 9 * 10 is 90 which leaves you with the numbers 14 and 3 we used 10 so that gives us 4 and 3 multiply those and you get 12 so add 12 to 90 and you get 102 thus the answer is A
(Urgent) Worth 10 points 7.3
Answer:
m∡CBD = 135°
Step-by-step explanation:
m + 3m = 180
4m = 180
m = 180/4
m = 45
angle CBD is 3(45) = 135 degrees
NEEDED ASAP PLZ!!!!!!!!!
The social studies teacher wants to know whether the students in the entire school prefer a model United Nations activity or a student government activity. The teacher draws a random sample from the following groups:
All teachers in the school
All boys in each grade
All students in each grade
All students in the social studies club
Which group best represents the population he should take a random sample from to get the best results for his survey? (5 points)
Group of answer choices
All teachers in the school
All boys in each grade
All students in each grade
All students in the social studies club
Answer:
All students in each grade
Which expression is equivalent to 4(5r+9)?
The ratio of tables to chairs at the furniture store is 1:6. There are 30 chairs. How many tables are there?
Answer:
5 : 30
Step-by-step explanation:
30/6 = 5
1 * 5 = 5
5 : 30
Hope it helps
Please mark me as the brainliest
Thank you
Please answer quick just super small explanation pls hurry quick for brainlessly answerr
Answer:
A
Step-by-step explanation:
2x/√2
2x/√2 x √2/√2 = 2x√2/2
x√2
A helicopter hovers 1500 feet above a small island. The
figure shows that the angle of depression from the
helicopter to point P is 40°.
How far off the coast, to the nearest foot, is the island?
400
1500ft
Please help me solve this problem
Answer:
the island is 1787.63ft far.
Step-by-step explanation:
<P=40° alternate angle
in triangle
relationship between perpendicular and base is given by tan angle
tan 40=p/b
tan40=1500/b
b=1500/tan40=1787.63ft
Can someone help with this math problem please
Answer:
0.40p-20
Step-by-step explanation:
hope this helps.
10 Mrs. Randall bought tickets to the art museum for all the fifth-grade students. Each ticket cost $12, and the total cost of the tickets was $1,152. How many fifth-grade students are there?
Answer:
Step-by-step explanation:
12s=1152 (divide each side by 12 to isolate s)
s=96
So there were 96 students.
Work out m and c for the line:
y = x + 3
Step-by-step explanation:
Given equation
y = x + 3
Comparing with y = mx + c so
Slope (m) = 1
y-intercept (c) = 3
Hope it will help :)❤
Answer:
I don’t know if this is right, but I hope this helps!
Step-by-step explanation:
Please no links, will report!
9514 1404 39318
Answer:
XY = 11.25
Step-by-step explanation:
Corresponding sides are proportional, so ...
XY/AB = XZ/AC
XY = (AB)(XZ/AC) = 5(18/8)
XY = 11.25
Which point is on the graph of y = 4x + 2? A (-2, -5 o B. (-4, -15) C. (4. 18) D. (0.1)
Answer:
The answer should be C
Step-by-step explanation:
I hope that helps you!
HELpPppPppPppPpppPppPppppppppppppppppppoopppppoppopppppppppp
Jdjxjjxx
Answer:
£140
Step-by-step explanation:
First count up the amount of full squares, then you see the partially filled squares and try find the match for it to fill the square. It ends up being 24 squares, meaning 24 square feet. That multiplied by £5, as that is the cost of red wood, gives you the answer of £140
A coin is tossed 100 times. WHich portion would you use to find how many times you'd expect the coin to land on heads?
Answer:
i would use 1/2 because theres 2 sides on a coin and if you flip it 100 times then the probability of it landing on heads is about 50 out of 100
Step-by-step explanation:
Can I please have help I will mark brainly est
Answer:
Hey mate......
Step-by-step explanation:
This is ur answer......
I believe its SQUARE! Cuz it says 4 right angles.....Hope it helps!
mark me brainliest pls.....
Follow me! :)
Anthony needs some kitchen
appliances He found a mixer
for $90 and a microwave for
$42 What is the total bill
after adding 8% sales tax?
The amount that Jimmy paid for his meals the four days, $6.45, $21.38, $1.99, $7.99, $16, $0, $7.99, $18.95, $4.30, $10.35, $18.20. Calculate the median
Answer:
$7.99
Step-by-step explanation:
Arrange numbers in numerical order: $0, $1.99, $4.30, $6.45, $7.99, $7.99, $10.35, $16, $18.20, $18.95, $21.38.
Count how many numbers you have, 11.
11 is an odd number so, the number in the middle of the data set is the median.
Final answer: $7.99 is the median.
Find the lateral surface area of the figure below. Round the the nearest tenths place.
help please !
Can someone please just help me with 1-3 I’ll mark brainliest it’s urgent?
Answer:
In the instruction above, it gives us some helpful information.
2 days with no professional sports game.
3 forms of ratio --> a to b, a : b, a / b
1) Remember there are 365 days in a year.
Days without games to Days in a year --> 2 to 365
Days without games : Days in a year --> 2 : 365
Days without games / Days in a year --> 2 / 365
2) Now there is a plot twist. It ask days with games. To find that we need to subtract 365 - 2 = 363 days with games.
Days with games to Days in a year --> 363 to 365
Days with games : Days in a year --> 363 : 365
Days with games / Days in a year --> 363 / 365
3) Days with games to Days without games --> 363 to 2
Days with games : Days without games --> 363 : 2
Days with games / Days without games --> 363 / 2
Hope this helps and sorry for not answering you. For some reason I was not getting any notification, but it is fixed now. Thank you :) !!
What is equivalent to 0 = 2x2 - 16x – 18 when completing the
square?
Answer:
x = 1
x = -9
Step-by-step explanation:
(2x2 + 16x) - 18 = 0
2x2 + 16x - 18 = 2 • (x2 + 8x - 9)
x2 + 8x - 9
-9 + 1 = -8
-3 + 3 = 0
-1 + 9 = 8
2 • (x + 9) • (x - 1) = 0
2 = 0
x+9 = 0
x = -9
x-1 = 0
x = 1
x2 + 8x - 9 = 0
x2+8x = 9
(x+4) • (x+4) =
(x+4)2
x2+8x+16 = 25 and
x2+8x+16 = (x+4)2
(x+4)2 = 25
x = -4 + √ 25
x2 + 8x - 9 = 0
has two solutions:
x = -4 + √ 25
or
x = -4 - √ 25
- B ± √ B2-4AC
x = ————————
2A
A = 1
B = 8
C = -9
B2 - 4AC =
64 - (-36) =
100
-8 ± √ 100
x = —————
2
x = ( -8 ± 10) / 2
x =(-8+√100)/2=-4+5= 1.000
or:
x =(-8-√100)/2=-4-5= -9.000
Answer: x = 1
x = -9
WEEEEEEEEELLLLLLLLLLLL What is 1+1 :0 too confusion for my 1 braincell
Answer:
WELLLLLLLLLLLLLLLLLLLLLL it's 11 obviously. (or 2 ;P)
Step-by-step explanation:
i have 1/2 of a braincell :)
Answer:
1 + 1 is 2 BUT
2 + 2 is 5 ILLUMIATI CONFIRMED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Step-by-step explanation:
Evaluate-n, when n=-4
Answer:
4
Step-by-step explanation:
-n =
-(-4) =
+4 =
4
Hope that helps!
-Sabrina
y=3/2x-9
I need to find the x-intercept and the y-intercept with work plsss
Hi there!
x-int: (6, 0)
y-int: (0, -9)
y = 3/2x - 9
Begin by finding the x-intercept. The x-intercept is located where y = 0, therefore:
0 = 3/2x - 9
Isolate for x by adding 9 to both sides:
9 = 3/2x
Divide both sides by 3/2x:
9 * 2/3 = x
x = 6. Thus, the x-intercept is at (6, 0).
Find the y-intercept by finding the y-value at which x = 0:
y = 3/2(0) - 9
y = -9. The y-intercept is at (0, -9).
What is the definition of an irrational number?
A.
a negative number
B.
a number that can be expressed as a fraction, , where p and q are integers and q is not equal to zero
C.
a number that cannot be expressed as a fraction, , where p and q are integers and q is not equal to zero
D.
a number that can be written as a fraction but not as a decimal
Which expressions represent the statement “three minus the product of seven and four”? Mark all that apply.
A 3 - (7 x 4)
B (7 x 4) - 3
C 3 - (4 / 7)
D 3 - (4 x 7)
E (7 x 4) - 3
The statement three minus the product of seven and four is given by the expression 3 - (7 * 4)
What is an equation?An equation is an expression used to show the relationship between two or more numbers and variables.
Given the statement three minus the product of seven and four, this is an expression:
3 - (7 * 4)
The statement three minus the product of seven and four is given by the expression 3 - (7 * 4)
Find out more on equation at: https://brainly.com/question/2972832