Suppose scores on exams in statistics are normally distributed with an unknown population mean and a population standard deviation of three points. A random sample of 36 scores is taken and gives a sample mean of 68. Find a 85 % confidence interval estimate for the population mean exam score. Explain what the confidence interval means
this the answer of queastions
Step-by-step explanation:
67.18,68.82
Let mu be the true population mean of statistics exam scores. We have a large random samples of n=36 scores with a sample mean of 68.we know that the population standard deviation is sigma=3.A pivotal quantity is 3^sqrt(36)=(3/6)=68(1/2) which is approximately normally distributed. Therefore the 85%confidence interval is 68-(1/2)(1.6449), 68+(1/2)(1.6449) i.e (67.18,68.82)
can someone please help with answer and explanation
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Answer:
(x, y) = (3, 12)
Step-by-step explanation:
The first step in any problem solving is to look at the problem. Here, we see that the first equation can be reduced to standard form by dividing it by 2. This would give both terms a coefficient of 1.
We see that the second equation already has a variable with a coefficient of 1.
When solving a system by substitution, it can save some effort if you start by finding a variable with a coefficient of 1 or -1. Since we see that in the second equation, we choose to solve the second equation for y:
y = 4x . . . . . . . add 4x to both sides of the second equation
Now, we have an expression for y that we can substitute into the first equation.
2x +2(4x) = 30 . . . . substitute for y
10x = 30 . . . . . . . . simplify
x = 3 . . . . . . . . . . divde by 10
y = 4(3) = 12 . . . . . find y using y=4x
The solution is (x, y) = (3, 12).
__
Additional comment
I doesn't matter what variable gets substituted. The purpose of the exercise is to reduce the number of variables in the equation. Here, we start with an equation that has 2 variables. Substituting for one of them gives an equation with only one variable, a lot easier to solve.
You don't have to find an expression for the "bare" variable. We could solve the second equation for 2x, for example: 2x = y/2, then substitute for 2x in the first equation: y/2 +2y = 30 ⇒ y = (2/5)(30) = 12. Or, we could solve the first equation for 2x and substitute into the second: 2x=30-2y, y-2(2x) = 0 ⇒ y-2(30-2y) = 0 ⇒ y = 60/5 = 12.
The substitution property of equality says you can make any substitution of equal values anywhere. "butter = margarine" means you can substitute butter for margarine, or vice versa, wherever you may wish.
In the picture below, which lines are lines of symmetry for the figure?
A. only 3
B. 1 and 3
C. 1, 2, and 3
D. none
Based on the lines drawn on the given picture, the number of lines of symmetry are D. none.
What are lines of symmetry?Lines of symmetry are those that divide a shape such that each side can be said to be a reflection of the other.
In the above image, there are no lines of symmetry because when any of the lines given divides the shape, either side would not be identical.
Find out more on lines of symmetry at https://brainly.com/question/23974310.
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if chaka,ada and ese are to share 120 oranges with the ratio of 1:2:3 respectively. How many oranges does ada have?.
Answer:
40
Step-by-step explanation:
1+2+3=6
1/6×120=20
2/6×120=40
3/6×120=60
NO LINKS OR ANSWERING QUESTIONS YOU DON'T KNOW. Find each measurement indicated. Round your answers to the nearest tenth. Part 3ddd
Answer:
see below
Step-by-step explanation:
7. We can use the law of sines to solve
sin C sin B
-------- = ----------
AB AC
sin 45 sin 32
--------- = ----------
AB 6
Using cross products
6 sin 45 = AB sin 32
6 sin 45 / sin 32 = AB
8.00620 = AB
To the nearest tenth
8.0= AB
9. We can use the law of sines to solve
sin A sin B
-------- = ----------
CB AC
sin A sin 88
-------- = -----------
13 15
Using cross products
15 sin A = 13 sin 88
sin A = 13/15 sin 88
Taking the inverse sin of each side
sin^-1(sin A) = sin ^-1 (13/15 sin88)
A = 60.01298726
To the nearest tenth
A =60.0
Simplify this radical.
90
3/10
6/10
9/10
103
Need help please on this
Answer:
3[tex]\sqrt{10}[/tex]
Step-by-step explanation:
Assuming you mean [tex]\sqrt{90}[/tex]
Using the rule of radicals
[tex]\sqrt{a}[/tex] × [tex]\sqrt{b}[/tex] ⇔ [tex]\sqrt{ab}[/tex] , then
[tex]\sqrt{90}[/tex]
= [tex]\sqrt{9(10)}[/tex]
= [tex]\sqrt{9[/tex] × [tex]\sqrt{10}[/tex]
= 3[tex]\sqrt{10}[/tex]
Help needed!!!
Find the length of the segment indicated.
A. 12.1
B. 16.4
C. 13.3
D. 11.4
Answer:
A
Step-by-step explanation:
using the theorem of Pythagoras
x = sqrt* 19.6 ^2 - 15.4^2*
x = 7× sqrt* 3*
x = 12.1 units
Answer:
A.) 12.1
Step-by-step explanation:
I got it correct on founders edtell
Damaged items are marked down 25% to 40%. A newspaper coupon holder; to an additional 10% markdown of the new price due to the damage. What is the lowest price of a damaged item that was originally marked GHC100?
A GHC 35.60
B GH 5000
C. GHC 18.00
D. GHC 40.80
E GHC 23.40
Markdown is the difference (at sale) between the price an item is placed at for retail sale, and the actual price the item is sold
The correct option is; B. GHC 50.00
The reason for choosing option B is as follows;
The known parameters
The percentage by which damaged items are marked down = 25% to 40%
The percentage markdown offered by the newspaper coupon = 10%
The original marked price of the item = GHC 100
Strategy:
Apply the damaged items and coupon markdown percentages to the original marked price of GHC100 sum the results to find the total markdown
Solution:
Markdown due to damage:
Given that the item is damaged, to have the lowest price, we apply the largest markdown of 40%;
40% is removed from the price to which the item marked down due to damage, as follows;
The markdown due to damage = 40/100 × GHC 100 = GHC 40
Markdown due to Coupon Holder:
The markdown the coupon holder is to get = 10% off the retail price
Given that the damage is not mentioned in the newspaper, we have;
∴ The markdown the coupon holder is to get = 10/100 × GHC 100 = GHC 10
Total markdown:
The total markdown is therefore equal to GHC 40 + GHC 10 = GHC 50
The Lowest Price of A Damaged Items marked GHC100:
The lowest price of the item = Original price - Maximum markdown
The lowest price of the item = GHC 100 - GHC 50 = GHC 50
Learn more about markdown and markup concepts here;
https://brainly.com/question/20705786
look at the image below plz correct answers Surface area of cones 15 points
Answer:
[tex]A\approx 282.7\ m^2[/tex]
Step-by-step explanation:
1. Approach
The easiest method to solve this problem is to use the Pythagorean theorem to find the height of the cone. Then one can substitute the values given and found on the cone into the formula to find the surface area in order to solve for the surface area of the given cone.
2. Height of the cone
Imagine drawing a line from the tip of the cone down to the center of the base. This line will form a right angle with the base, thus, a right triangle is formed between the line, the radius (the distance from the center to the circumference or outer edge on a circle) of the base, and the incline of the cone. The Pythagorean theorem is a formula that relates the sides of a right triangle. This formula is as follows:
[tex]a^2+b^2=c^2[/tex]
Where (a) and (b) are the legs or the sides adjacent to the right angle of the right triangle, and (c) is the hypotenuse or the side opposite the right angle of the right triangle. Substitute the given values into the formula and solve for the unknown, or rather the height of the cone:
[tex]a^2+b^2=c^2[/tex]
[tex]a^2+5^2=13^2[/tex]
Simplify,
[tex]a^2+5^2=13^2[/tex]
[tex]a^2+25=169[/tex]
Inverse operations,
[tex]a^2+25=169[/tex]
[tex]a^2=144[/tex]
[tex]a=12[/tex]
[tex]h=12[/tex]
3. Find the surface area of the cone.
The following formula can be used to find the surface area of a cone:
[tex]A=\pi r(r+\sqrt{h^2+r^2})[/tex]
Where ([tex]\pi[/tex]) represents the numerical value (3.1415...), (r) represents the radius of the base, and (h) represents the height of the cone. Substitute the given values into the formula and solve for the surface area:
[tex]A=\pi r(r+\sqrt{h^2+r^2})[/tex]
[tex]A=\pi 5(5+\sqrt{12^2+5^2})[/tex]
Simplify,
[tex]A=\pi 5(5+\sqrt{12^2+5^2})[/tex]
[tex]A=\pi 5(5+\sqrt{144+25})[/tex]
[tex]A=\pi 5(5+\sqrt{169})[/tex]
[tex]A=\pi 5(5+13)[/tex]
[tex]A=\pi 5(18)[/tex]
[tex]A=\pi 90[/tex]
[tex]A\approx 282.743[/tex]
A basketball player averages 22.5 points scored per game with a standard deviation of 6.2 points. In one game, the athlete scored 10 points. What is the z-score for the points scored in this game?
–2.02
–1.63
1.63
2.02
Answer:
Step-by-step explanation:
Z -2.02
x 10
µ 22.5
σ 6.2
HELP PLEASE!!!!
The median age for a first marriage in the United States for women was 25.9 in 2009 and 26.1 in 2010. Use an exponential model to predict the median age for women in 2019, where x is the number of years since 2009.
A) 23.9
B) 28.3
C) 28.0
D) 24.0
Answer:
29.1 Is the answer for 2009
Step-by-step explanation:
Quadrilateral JKLM is rotated - 270° about the origin.
Draw the image of this rotation
Need a visual answer please! Thanks!
Answer:
Step-by-step explanation:
When the quadrilateral JKLM is rotated - 270° about the origin then the image of rotated quadrilateral is shown below.
What is rotation?"It is a transformation in which the object is rotated about a fixed point. "
For given question,
Quadrilateral JKLM is rotated - 270° about the origin.
This means, quadrilateral JKLM is rotated 270° clockwise about the origin.
We know, if point P(x, y) is rotated 270° clockwise or 90° anticlockwise then the coordinated of rotated point would be (-y, x).
From figure, the coordinates of the quadrilateral JKLM are:
J = (3, 3)
K = (5, -5)
L = (-3, -7)
M = (3, -3)
After rotating -270° about the origin the coordinates of the quadrilateral would be,
J' = (-3, 3)
K' = (5, 5)
L' = (7, -3)
M' = (3, 3)
And the image of the rotated quadrilateral J'K'L'M' is shown below.
Therefore, when the quadrilateral JKLM is rotated - 270° about the origin then the image of rotated quadrilateral is shown below.
Learn more about rotation here:
https://brainly.com/question/16710736
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The midpoint of has coordinates of (4, -9). The endpoint A has coordinates (-3, -5). What are the coordinates of B?
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Answer:
(11, -13)
Step-by-step explanation:
If midpoint M is halfway between A and B:
M = (A +B)/2
Then B is ...
B = 2M -A
B = 2(4, -9) -(-3, -5) = (8+3, -18+5)
B = (11, -13)
Answer:
Use the midpoint formula:
[tex]midpoint=(\frac{x_{1}+x_{2}}{2}, \frac{y_{1}+y_{2}}{2})[/tex]
Endpoint A = (x₁, y₁) = (-3, -5)Endpoint B = (x₂, y₂)Midpoint = (4, -9)Substitute in the values:
[tex](4, -9)=(\frac{-3+x_{2}}{2} +\frac{-5+y_{2}}{2} )[/tex]
[tex]4=\frac{-3+x_{2}}{2} \\4(2)=-3+x_{2}\\8+3=x_{2}\\x_{2}=11[/tex] [tex]-9=\frac{-5+y_{2}}{2} \\(-9)(2)=-5+y_{2}\\-18+5=y_{2}\\y_{2}=-13[/tex]
Therefore, Point B = (11, -13)
In a 4 day period, a delivery person delivered the following number of
packages per day: 1150, 1200, 1900 and 1350. The average number of
packages he delivered per day was _?_
Answer: 1400 packages
Step-by-step explanation:
1150+1200+1900+1350 divided by the 4 day interval means and average of:
1400 packages per day
The quotient of -8 and the sum of a and b
Hi! I'm happy to help!
To solve this, you need to know what all of the terms mean. Quotient means division, and sum means addition. Knowing this we can set up our expression.
Because there is an operation inside of an operation (addition inside of division) we use parenthesis.
-8÷(a+b)
I hope this was helpful, keep learning! :D
the mean salary if of 5 employees is $35900. the median is $37000. the mode is $382000. If the median payed employee gets a $3100 raise, then…
New median:
New mode:
Answer:
Step-by-step explanation:
New median:40100
New mode:385100
Find the surface area of the rectangular prism below.
Answer:
Option B
Step-by-step explanation:
This is the formula :
2(wl+hl+hw)
Step 1 : Take the length, width, and height and substitute the values in.
The required surface area of the rectangular prism is 461.02 square meters (m²).
What is surface area?Surface area is defined as the measure of a region or surface is called as surface area.
The surface area of a rectangular prism can be calculated by adding up the areas of all six faces. The formula for the surface area of a rectangular prism is:
Surface area = 2lw + 2lh + 2wh
where l, w, and h are the length, width, and height of the rectangular prism, respectively.
Substituting the given values, we get:
Surface area = 2(12.3m x 4.3m) + 2(12.3m x 10.7m) + 2(4.3m x 10.7m)
Simplifying the expression gives:
Surface area = 461.02m²
Therefore, the surface area of the rectangular prism is 461.02 square meters (m²).
Learn more about the surface area here: https://brainly.com/question/2835293
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Please help meeee
Find the value of d.
A. 47
B. 56
C. 75
D. 30
Answer:
56
Step-by-step explanation:
Angle Formed by Two Chords= 1/2(sum of Intercepted Arcs)
75 = 1/2 (94+d)
Multiply by 2
75*2 = 94+d
150 = 94+d
Subtract 94 from each side
150-94 = d
56=d
For the inequality 4 < -x^2– y, where is the graph shaded and is the curve solid or dotted"
answer=
X<-4
.............................................................
Determine what type of model best fits the given situation:
A. linear
B. exponential
O c. quadratic
D. none of these
Reset Selection
Most of the heat loss for outdoor swimming pools is due to surface
evaporation. So, the greater the area of the surface of the pool, the greater
the heat loss. For a given perimeter, which surface shape would be more
efficient at retaining heat: a circle or a rectangle? Justify your answer.
Answer:
rectangle
Step-by-step explanation:
Perimeter of 20 feet
rectangle (square is technically a rectangle):
sides 5 and 5
5*5 = 25ft²
Circle:
20/(2π) = 3.18309...
3.1809...²π = 31.831ft²
Max area of rectangle (i.e. square) has a smaller area than a circle.
Can someone please help solve this equation thank you
Answer:
A and B
Step-by-step explanation:
Both points are in the shaded/blue zone
I hope this helps!
pls ❤ and give brainliest pls
Answer:
Yea both A and B are correct.
Step-by-step explanation:
if you can see you can put (-12,0) inside the shaded triangle also for (-10,1)
you can give brainlist to the person above :D
Which function represents the graph below?
Answer:
The inequalities all need to be of the form a < x ≤ b. Only the first selection matches that requirement.
Step-by-step explanation:
The population p(t) of a culture of the bacterium Pseudomonas aeruginosa is given by ,p(t)= -1683t^2+75,000t+ 10,000 where is the time in hours since the culture was started. Determine the time the population was at its maximum. Round to the nearest hour.
Answer:
22hrs
Step-by-step explanation:
hope it is well understood?
Kayla parks her car at the corner of Ogilvie and Montreal Rd. She walks 80m East and then turns 30° to the left towards her office building and continues walking for another 100m until she reaches her building. She then takes the elevator to her office 60m above ground level and looks out the window. She can see her car from here. How far is it from where she is to her car in a direct line?
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Answer:
184 m
Step-by-step explanation:
The direct distance from Kayla's car (C) to the door of her office building (B) can be found using the Law of Cosines. The interior angle of the triangle at the turning point is 180° -30° = 150°, so the distance is ...
t² = b² +c² -2bc·cos(T)
t² = 80² +100² -2·80·100·cos(150°) = 30256.406
The direct distance from her window to the car can be found from the Pythagorean theorem. The legs of the right triangle are the distance from the car to the building (CB) and the height from the building entrance to the window (BW).
CW = √(t² +60²) ≈ 184.001
The direct line distance from Kayla to her car is 184 meters.
_____
For the first computation, we used the usual notation for a triangle, where capital letters (CTB) are the vertices and angles, and corresponding lower-case letters are their opposite sides.
NEED HALP!!! Find the ordered pair $(s,t)$ that satisfies the system
Answer:
(-8/7 ; 5/7)
Step-by-step explanation:
5t + 1/2s = 3 - - - (1)
3t - 6s = 9 - - - - - (2)
Multiply (1) by 12 and (2) by 1
Add the result to eliminate s
60t + 6s = 36
3t - 6s = 9
____________
63t = 45
t = 45 / 63
t = 5/7
Put t = 5/7 in either (1) or (2) to obtain the value of s
3(5/7) - 6s = 9
15/7 - 6s = 9
-6s = 9 - 15/7
-6s = (63 - 15)/7
-6s = 48/7
s = 48/7 * - 1/6
s = - 8/7
Lainey is looking for a new apartment and her realtor keeps calling her with new listings . The calls only take a few minutes , but a few minutes here and there are really starting to add up . She's having trouble concentrating on her work . What should Lainey do ? a ) Tell her realtor she can only receive text messages b ) Limit the time spent on each call c ) Turn off her phone until she is on a break d ) Call her realtor back when customers won't see her on the phone
Answer:
c ) Turn off her phone until she is on a break
Use AABC shown below to answer the question that follows:
Which of the following is a step towards proving the similarity of triangle so AABC and ADBA? (5 points)
Segment BC is a hypotenuse.
Angle B is congruent to itself.
Segment BA is shorter than segment BC.
Segment BC is intersected by segment AD.
Answer:
Bc is intersected by segment AD
Answer:
Bc is intersected by segment AD
Step-by-step explanation:
Solve for 2x^2=50
Please help
Answer:
Equation:
2x^2 = 50
Divide by 2:
x^2 = 25
Take the square root:
x = 5, or -5.
Let me know if this helps!
Answer:
x=5
x=−5
Step-by-step explanation:
A family are going away for the weekend. They look at a road map to see where their hotel is.
The scale used is 1:250,000
The distance to their hotel measures 8.5 cm on the map.
What is the actual distance?
km
Answer:
106.25km
Step-by-step explanation:
8.5cm = 0.000085km
map:real life
1:1250000
0.000085km : 0.000085km * 1250000 = 106.25km
