Answer:
[tex]y= -x^{2} -2x+15[/tex]
Step-by-step explanation:
[tex]y= -x^{2} -2x+15[/tex]
The method of tree-ring dating gave the following years A.D. for an archaeological excavation site. Assume that the population of x values has an approximately normal distribution.
1,2851,1871,2221,1941,2681,3161,2751,3171,275
Required:
a. Use a calculator with mean and standard deviation keys to find the sample mean year x and sample standard deviations.
b. Find a 90% confidence interval for the mean of all tree-ring dates from this archaeological site. (Round your answers to the nearest whole number.)
Answer:
a) The sample mean is 1260 and the standard deviation is 48.
b) The 90% confidence interval for the mean of all tree-ring dates from this archaeological site is (1230, 1290).
Step-by-step explanation:
Question a:
Mean is the sum of all values divided by the number of values. So
[tex]\overline{x} = \frac{1285 + 1187 + 1222 + 1194 + 1268 + 1316 + 1275 + 1317 + 1275}{9} = 1260[/tex]
Standard deviation is the square root of the sum of the differences squared between each value and the mean, divided by the one less than the sample size. So
[tex]s = \sqrt{\frac{(1285-1260)^2 + (1187-1260)^2 + (1222-1260)^2 + (1194-1260)^2 + (1268-1260)^2 + ...}{8}} = 48[/tex]
The sample mean is 1260 and the standard deviation is 48.
Question b:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom,which is the sample size subtracted by 1. So
df = 9 - 1 = 8
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 8 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 1.8595
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 1.8595\frac{48}{\sqrt{9}} = 30[/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 1260 - 30 = 1230
The upper end of the interval is the sample mean added to M. So it is 1260 + 30 = 1290
The 90% confidence interval for the mean of all tree-ring dates from this archaeological site is (1230, 1290).
A bag contains 3 red, 5 blue, and 4 white marbles. If a marble is drawn from the bag, not replaced, and another is drawn, what is the probability of selecting a white and then blue marble?
Answer:
5/33
Step-by-step explanation:
The probability of selecting a white marble is 4/12 = 1/3(because we have 4 white marbles and 12 marbles in total )
The probability of selecting a blue marble is 5/11 (because we have 5 blue marbles and 11 marbles left(1 has been drawn already) )
Probability of selecting a white and then blue marble equals 1/3*5/11 = 5/33
Find hypotenuse,perpendicular and base
Answer:
Consider the angle Ф.
the line opposite to Ф is the perpendicular -> PQ = 5cm
The base is the line with whom the perpendicular has 90° angle -> PR = 12cm
Finally, hypotenuse is the line opposite to the 90° which is QR= 13cm
Answer:
hypotenuse = QR = 13 cm
Perpendicular = PQ = 5 cm
Base = PR = 12 cm
What types of concurrent constructions are needed to find the incenter of a triangle?
A. intersection of the lines drawn from each vertex of the triangle and perpendicular to its opposite side
B. intersection of the lines drawn to the midpoint of each side of the triangle to its opposite vertex
C. intersection of the lines drawn perpendicular to each side of the triangle through its midpoint
D. intersection of the lines drawn to bisect each vertex of the triangle
Plz help’
!
I’ll be giving extra points
because it's value will always be same
Answer:
This value doesn't depend on x or y
It'll be the same things always
Find the missing side length. Leave your answers radical in simplest form. PLEASE HURRY
Answer:
the answer for y=4 and x=4✔3
Complete the pattern ___ 8,579 ____85.7 8.57____
Answer:
the next one is .857 I hope this helps you :)
fill in each balance???
Answer:
Step-by-step explanation:
Take the beginning number and add or subtract each transaction to get a new balance. For example,
349.45
- 23.42 = 326.03
- 14.95 = 311.08
+ 276.50 = 587.58
- 219.93 = 367.65
- 76.84 = 290.81
Which statement explains how you could use coordinate geometry to prove that quadrilateral ABCD is a square
Answer:
Prove that all sides are congruent and that the slopes of consecutive sides are opposite reciprocals. Step-by-step explanation: In order to two segmets to be perpendicular, the slope of both lines must be opposite and reciprocals, having a 90° interception and forming a square.
(x2 + 3x + 1) + (2x2 + 2x)
HINT
Answer:
3x^2+5x+1
Step-by-step explanation:
(x^2 + 3x + 1) + (2x^2 + 2x)
Combine like terms
x^2 + 2x^2 + 3x +2x +1
3x^2+5x+1
Answer:
[tex]3x^{2} + 5x + 1[/tex]
Step-by-step explanation:
Step 1: Combine like terms
[tex](x^{2} + 3x + 1) + (2x^{2} + 2x)[/tex]
[tex](x^{2} + 2x^{2} + (3x + 2x) + (1)[/tex]
[tex]3x^{2} + 5x + 1[/tex]
Answer: [tex]3x^{2} + 5x + 1[/tex]
Scores on a national English test are Normally distributed, with a mean score of 510 and a standard deviation of 75. Sixty-eight percent of English tests were less than which score, rounded to the nearest whole number?
A) 475
B) 529
C) 545
D) 561
Answer:
Should be (C). Can't verify.
545
ED2021
Point-Slope Form of a Line
what is the value of sum of 18 and 3 time the difference of 9 and 5 divided by 2 is subtracted from 30 ?
if u give right answer i will mark u as a brainlist
Answer:
12
Step-by-step explanation:
(18+3)=21
(9-5)=4
4x21=84
84/2=42
42-30=12
Answer:
12
Step-by-step explanation:
((18+3)x(9-5))/2-30
=((21)x(4))/2-30
=(84)/2-30
=42-30
=12
Calculate the next term in the geometric sequence that is calculated with a ratio of 19 if the current term is 38
Answer:
Step-by-step explanation:
The next term is going to be simply 38*19 = 722
The series is geometric which means that you multiply from one term to get to the next.
The ratio of 19, and the current term is 38. So to get to the next term, multiply 38 * 19
forty-five percent of the students in a dorm are business majors and fifty-five percent are non-business majors. business majors are twice as likely to do their studying at the library as non-business majors are. half of the business majors study at the library. if a randomly slected student from the dorm studies at the library, what is the probability the student is a business major
Solution :
Defining the following events as :
B : Being a Business major
α : Studying at the library
∴ Given that :
[tex]$P(B) = \frac{45}{100}$[/tex]
= 0.45
Again, P [ Studying at the library | Being a Business major ] = 2 P [ Studying at the library | Being a non business major ]
[tex]$P[ \alpha | B] = 2 P[\alpha | B^C]$[/tex] .......(1)
Again,
[tex]$P[\text{Studying at the library } | \text{ Being a business major}] = \frac{1}{2} = 0.50$[/tex]
[tex]$P(\alpha | B) = 0.50$[/tex]
From (1), we get
[tex]$P(\alpha | B^C) = \frac{1}{2} . P(\alpha | B)$[/tex]
[tex]$=\frac{1}{2} \times 0.50$[/tex]
= 0.25
Therefore, we need,
= P[ The students is a Business major | The student studies at the library ]
[tex]$=P(B | \alpha)$[/tex]
By Bayes theorem
[tex]$=\frac{P(B). P(\alpha | B)}{P(B).P(\alpha | B) + P(B^C). P(\alpha | B^C)}$[/tex]
[tex]$=\frac{0.45 \times 0.50}{0.45 \times 0.50 + 0.55 \times 0.25}$[/tex]
= 0.6207
1 gallon = 3.8 liters 1 mile = 1.6 kilometers using the conversion above,a bus that uses that uses 10 liters of gasoline to travel 10 liters of gasoline to travel 100 kilometers would have an efficiency rating closest to a) 15 miles per gallon b) 24 miles per gallon c) 38 miles per gallon d) 60 miles per gallon
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Answer:
b) 24 miles per gallon
Step-by-step explanation:
The usual metric measure of vehicle fuel efficiency is liters per 100 km. Greater efficiency is indicated by a lower value.
In the US, the measure is usually miles per gallon. Greater efficiency is indicated by a higher value. Since we want the efficiency expressed in miles per gallon, we need to divide distance by fuel consumption.
(distance)/(fuel used) = (100 km)/(10 L)
= (100 km)/(10 L) × (1 mi)/(1.6 km) × (3.8 L)/(1 gal) = (100×3.8)/(10×1.6) mi/gal
= 23.75 mi/gal ≈ 24 mi/gal
Which is the
Simplified form
r-7+s-12
Answer:
r + s - 19
General Formulas and Concepts:
Algebra I
Terms/CoefficientsStep-by-step explanation:
Step 1: Define
Identify
r - 7 + s - 12
Step 2: Simplify
Combine like terms [constants]: r + s - 19Write the number 16,107,320 expanded form.
Answer:
Sixteen million, one hundred and seven thousand, three hundred twenty
Step-by-step explanation:
VG¯¯¯¯¯¯¯¯=12.2 in. PG¯¯¯¯¯¯¯¯=13.1 in. Find the radius of the circle.
Answer:iiii
Step-by-step explanation:iiiii
Answer:
17.9
Step-by-step explanation:
correct gets brainliest!
find an expression that can be added to the expression 3x + 2 to give 5x + 3.
Answer:
2x+1
Step-by-step explanation:
The expression = (5x+3)-(3x+2) = 2x+1
describe the effect of the transformation (x,y) --> (x,y+4)
First correct gets brainliest!
A) Vertical stretch without reflection
B) Vertical stretch with reflection
C) Horizontal translation of 4 units
D) Vertical translation of 4 units
Answer:
D. Vertical translation of 4 units.
Step-by-step explanation:
This transformation keeps x the same but shifts y up 4 units (adding 4 to it). This is a vertical shift up 4, which we can also call a vertical "translation."
I need help answer asap
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Answer:
A
Step-by-step explanation:
To form the conjugate, change the sign between terms. Leave the radical alone.
the conjugate is √(x-5) +2 . . . . matches choice A
[tex]\huge\bold\pink{ANSWER} [/tex]
===========================================
A
[tex] \sqrt{ \times - 5 + 2} [/tex]
tsurezure children
#BrainliestBunch
Evaluate.
(45)3
64/125
16/25
12/15
Answer:
64
------
125
Step-by-step explanation:
(4/5)^3
We can rewrite this as
4^3
----------
5^3
64
------
125
a shopkeeper marked price a article a certain price above the cost price and he allowed 16% discount to make 5% profit if a customer paid 9492 with 13% vat to buy it by what percent is the mp above cp
Answer:
if I had known this
Step-by-step explanation:
then I won't be using this app right now..
Find the unit price of each of the following items Round your answer to the nearest tenth
frozen orange juice
16.0% at $2.01
12 oz at $1.69
Answer:
12.56 cents
14.08 cent
Step-by-step explanation:
The unit price for each of the following items could be obtained thus :
The unit price = price of one item
Therefore, given that x numbers of a certain item cost y ;
The unit price will be : y / x
frozen orange juice
16.0 oz at $2.01
12 oz at $1.69
If 16 oz cost $2.01
1 oz = $2.01 / 16 = $0.125625 * 100 = 12.56 cents
If 12 oz = $1.69
1 oz = $1.69 / 12 = $0.1408333 * 100 = 14.08 cent
Is the relationship shown by the data linear? If so, model the data with an equation.
Answer:
The relation is linear
Step-by-step explanation:
Answer:
Yes, the relationship shown is linear. The equation of the line is y=-1.25x-13.25.
Step-by-step explanation:
This data is linear as y decreases at a constant rate. The equation of a line is y=mx+b, where m=slope and b=y intercept
To find m:
m=[tex]\frac{y2-y1}{x2-x1}[/tex]
m=[tex]\frac{(-2)-(-7)}{(-9)-(-5)}[/tex]
m=[tex]\frac{5}{-4}[/tex]
m=[tex]-\frac{5}{4}[/tex]=-1.25
To find b, you can use any of the given points:
(-9,-2)
(-2)=-1.25(-9)+b
-2=11.25+b
-2-11.25=b
b=-13.25
Therefore, using the calculated values for m and b:
y=mx+b
y=-1.25x-13.25
linear equation 7x+25=9
Answer:
x = -16/7
Step-by-step explanation:
7x+25=9
Subtract 25 from each side
7x+25-25=9-25
7x = -16
Divide each side by 7
7x/7 = -16/7
x = -16/7
Answer:
[tex]7x + 25 = 9 \\ 7x = 9 - 25 \\ 7x = - 16 \\ x = \frac{ - 16}{7} \\ x = - 2.29[/tex]
Step-by-step explanation:
I hope it helped U
stay safe stay happy
The ratio of the volumes of two similar solid polyhedra is equal to the square root of the ratio between their edges. True or False? HELP QUICK PLSSSSS
Answer:
FALSE.The ratio of the volumes of two similar solid polyhedra is equal to the square of the ratio between their edges. This statement is false. A polyhedron is a shape that has no gaps between their edges or vertices.
Answer:
it's false
~~~~~~~~~~~
Determine whether the integral from -3 to infinity 1/sqrt (5 - x) is divergent or convergent. If it is convergent, evaluate it. If not, state your answer as divergent .
It's divergent because 1/√(5 - x) is defined only for x < 5, which means the integral from 5 to infinity doesn't exist.
X cubed = 343^-1 find the positive value of x
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Answer:
x = 1/7
Step-by-step explanation:
x³ = 1/343
x = 1/∛343 = 1/7
The positive value of x is 1/7.
_____
Additional comment
A square root (or any even-index root) will have both positive and negative real values. A cube root (or any odd-index root) will have only one real value, whose sign will match the sign of the value being rooted.
343^(-1/3) is the cube root of a positive number, so it will be a positive real number.