Is a – b a positive number or a negative number? How do you know?
b b
a
1
Please help I will give you Brainlyest
Answer:
A positive number.
Any negative subtracted from a positive will always be positive.
Answer:
a-b will be and will always be a POSITIVE number.
This is because a is positive, and b is negative.
However, when you subtract a negative number, you are actually just adding it.
So, a - (-b) = a+b.
This is why, it will always be positive.
Let me know if this helps!
g(t) = -9 -4
-
9
(
= 23
Answer:
-3
Step-by-step explanation:
See attached image
Air is being pumped into a spherical balloon at the rate of 7 cm³/sec. What is the rate of change of the radius at the instant the volume equals 36n cm³ ? The volume of the sphere 47 [7] of radius r is ³.
the rate of change of the radius at the instant the volume equals 36π cm³ is 7 / (36π) cm/sec.
The volume V of a sphere with radius r is given by the formula V = (4/3)πr³. We are given that the rate of change of the volume is 7 cm³/sec. Differentiating the volume formula with respect to time, we get dV/dt =(4/3)π(3r²)(dr/dt), where dr/dt represents the rate of change of the radius with respect to time.
We are looking for the rate of change of the radius, dr/dt, when the volume equals 36π cm³. Substituting the values into the equation, we have: 7 = (4/3)π(3r²)(dr/dt)
7 = 4πr²(dr/dt) To find dr/dt, we rearrange the equation: (dr/dt) = 7 / (4πr²) Now, we can substitute the volume V = 36π cm³ and solve for the radius r: 36π = (4/3)πr³
36 = (4/3)r³
27 = r³
r = 3 Substituting r = 3 into the equation for dr/dt, we get: (dr/dt) = 7 / (4π(3)²)
(dr/dt) = 7 / (4π(9))
(dr/dt) = 7 / (36π)
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If PQ = 61, QR = 50, and TU = 10, find the length of ST. Round your answer
to the nearest tenth if necessary. Figures are not necessarily drawn to scale.
R
75
P
54°
U
T
54°
51°
S
The length ST of the triangle STU is 12.2 units.
How to find the side of similar triangle?Similar triangles are the triangles that have corresponding sides in
proportion to each other and corresponding angles equal to each other.
Therefore, using the similarity ratios, the side ST of the triangle STU can be found as follows:
Therefore,
PQ / ST = QR / TU
Hence,
61 / ST = 50 / 10
cross multiply
610 = 50 ST
divide both sides by 50
ST = 610 / 50
ST = 610 / 50
ST = 12.2 units
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A sample of ultrasonic humidifiers of one particular brand was selected for which the observations on maximum output of moisture (oz) in a controlled chamber were 14. 0, 14. 3, 12. 2, and 15. 1. A sample of a second brand gave output values 12. 1, 13. 6, 11. 9, and 11. 2 ("Multiple Comparisons of Means Using Simultaneous Confidence Intervals", J. Qual. Techn. , 1989). Assume that both brands have maximum moisture distributions with equal variances.
(a) Is there a difference in mean maximum output of moisture between the two brands? Set up the relevant hypotheses and test at the a =. 05 level, using the pooled procedure. Make sure to interpret your results in the context of the problem.
(b) Construct and interpret a 95% confidence interval to support your decision from (a)
a. There is sufficient evidence to conclude that there is a significant difference in the mean maximum output of moisture between the two brands of ultrasonic humidifiers.
b. We are 95% confident that the true difference in mean maximum output of moisture between the two brands of ultrasonic humidifiers lies between 0.394 oz and 3.006 oz.
To test if there is a difference in the mean maximum output of moisture between the two brands of ultrasonic humidifiers, we can set up the following hypotheses:
Null Hypothesis (H₀): The mean maximum output of moisture for both brands is equal.
Alternative Hypothesis (H₁): The mean maximum output of moisture for the two brands is different.
To perform the test, we will use the pooled procedure assuming equal variances. Let's calculate the necessary statistics and perform the hypothesis test.
(a) Hypothesis Testing:
Let's denote:
n₁ = sample size of Brand 1 = 4
n₂ = sample size of Brand 2 = 4
x₁ = sample mean of Brand 1 = (14.0 + 14.3 + 12.2 + 15.1) / 4 = 55.6 / 4 = 13.9 oz
x₂ = sample mean of Brand 2 = (12.1 + 13.6 + 11.9 + 11.2) / 4 = 48.8 / 4 = 12.2 oz
s₁ = sample standard deviation of Brand 1
s₂ = sample standard deviation of Brand 2
To calculate the pooled standard deviation (spooled), we use the following formula:
spooled = sqrt(((n₁ - 1) * s₁² + (n₂ - 1) * s₂²) / (n₁ + n₂ - 2))
Now, we can calculate the test statistic (t-value) using the formula:
t = (x₁ - x₂) / (spooled * sqrt(1/n₁ + 1/n₂))
Since we assume equal variances, we can combine the variances and degrees of freedom using the formula:
df = n₁ + n₂ - 2
We will compare the calculated t-value to the critical value from the t-distribution with (df) degrees of freedom to determine the result of the hypothesis test.
(b) Confidence Interval:
To construct a 95% confidence interval, we can use the formula:
CI = (x₁ - x₂) ± tα/2 * (spooled * sqrt(1/n₁ + 1/n₂))
where tα/2 is the critical value from the t-distribution corresponding to a significance level of α = 0.05 (two-tailed test) and (df) degrees of freedom.
Let's calculate the required values to perform the test and construct the confidence interval:
s₁ = sqrt((Σ(x - x')²) / (n₁ - 1))
= sqrt((14.0 - 13.9)² + (14.3 - 13.9)² + (12.2 - 13.9)² + (15.1 - 13.9)²) / (4 - 1)
≈ sqrt(0.01 + 0.16 + 1.69 + 1.21) / 3
≈ sqrt(4.07) / 3
≈ 1.07
s₂ = sqrt((Σ(x -x')²) / (n₂ - 1))
= sqrt((12.1 - 12.2)² + (13.6 - 12.2)² + (11.9 - 12.2)² + (11.2 - 12.2)²) / (4 - 1)
≈ sqrt(0.01 + 1.44 + 0.09 + 1) / 3
≈ sqrt(2.54) / 3
≈ 0.59
spooled = sqrt(((n₁ - 1) * s₁² + (n₂ - 1) * s₂²) / (n₁ + n₂ - 2))
= sqrt(((4 - 1) * 1.07² + (4 - 1) * 0.59²) / (4 + 4 - 2))
≈ sqrt((3 * 1.1449 + 3 * 0.3481) / 6)
≈ sqrt(3.4347 / 6)
≈ sqrt(0.5724)
≈ 0.757
t = (x₁ - x₂) / (spooled * sqrt(1/n₁ + 1/n₂))
= (13.9 - 12.2) / (0.757 * sqrt(1/4 + 1/4))
≈ 1.7 / (0.757 * sqrt(0.5))
≈ 1.7 / (0.757 * 0.707)
≈ 1.7 / 0.536
≈ 3.171
df = n₁ + n₂ - 2 = 4 + 4 - 2 = 6
Using a t-table or calculator, the critical value for a two-tailed test with α = 0.05 and df = 6 is approximately 2.447.
Since the calculated t-value (3.171) is greater than the critical value (2.447), we reject the null hypothesis.
Interpretation:
Based on the test results, there is sufficient evidence to conclude that there is a significant difference in the mean maximum output of moisture between the two brands of ultrasonic humidifiers.
Now, let's proceed to construct the confidence interval:
CI = (x₁ - x₂) ± tα/2 * (spooled * sqrt(1/n₁ + 1/n₂))
= (13.9 - 12.2) ± 2.447 * (0.757 * sqrt(1/4 + 1/4))
≈ 1.7 ± 2.447 * (0.757 * 0.707)
≈ 1.7 ± 2.447 * 0.534
≈ 1.7 ± 1.306
The 95% confidence interval is approximately (0.394, 3.006).
Interpretation:
We are 95% confident that the true difference in mean maximum output of moisture between the two brands of ultrasonic humidifiers lies between 0.394 oz and 3.006 oz.
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What is the volume of this right cone?
27 cm
200cm
213 cm
300 cm
a tea shop sells 42 varieties of boxes of tea. iroh purchases 5 boxes of tea. how many ways are there for iroh to make a selection if there is no restriction on the varieties of tea purchased from the shop?
use calculator to find both the compound amount and the interest on $7000 at 12% for 2 years. Interest is compounded quarterly. what is compound amount? round to the nearest cent as needed what is the Interest? Round to the nearest cent as needed
Compound amount = $8867.39
compound interest = $1867.39
EXPLANATION
Given:
Principal(p) = $7000 Rate(r) = 0.12 Time(t) = 2 n= 4
We can calculate the compound amount(A) using the formula below:
\(A=P(1+\frac{r}{n})^{nt}\)Substitute the values and evaluate.
\(A=7000(1+\frac{0.12}{4})^{4\times2}\)\(=7000(1+0.03)^8\)\(=7000(1.03)^8\)\(\approx8867.39\)Hence, the compound amount = $8867.39
We proceed to find the compound interest.
A = P + I
⇒ I = A - P
= 8867.39 - 7000
=1867. 39
Therefore, the compound interest = $1867.39
Someone pls help me ill give out brainliest pls don’t answer if you don’t know
Answer:
B
Step-by-step explanation:
√256=16
√289=17
Answer:
b.√256 and √289 . play basketball
which of the following values are in the domain of the function graphed below? check all that apply. 8 0 5 -1 9 -2
Answer:
cant answer without a function graphed
Step-by-step explanation:so yeah
Solve the open sentence.
-35n+6 57
ons-9 and ns6
n> 9 and ns 7
On-9 and ns1
ons 3 and ns 7
Answer:
-9 ≤n ≤1
Step-by-step explanation:
-3 ≤ n+6 ≤ 7
Subtract 6 from all sides
-3 -6≤ n+6-6 ≤ 7-6
-9 ≤n ≤1
In art class students are mixing black and white paint to make gray paint. Alexandra mixes 2 cups of black paint and 1 cup of white. Noah mixes 3 cups of black paint and 2 cups of white paint. Use Alexandra and Noah’s precent of black paint to determine whose gray paint will be darker.
Alexandra's mixture has a higher percentage of black paint, making it darker than Noah's mixture.
To determine whose gray paint will be darker, we can use the percentage of black paint in each mixture.
Alexandra's mixture contains 2 cups of black paint and 1 cup of white paint. This means that the percentage of black paint in her mixture is 2/(2+1) = 2/3, or about 66.67%.
Noah's mixture contains 3 cups of black paint and 2 cups of white paint. This means that the percentage of black paint in his mixture is 3/(3+2) = 3/5, or about 60%.
Based on these percentages, we can see that Alexandra's mixture has a higher percentage of black paint, making it darker than Noah's mixture. Therefore, Alexandra's gray paint will be darker than Noah's gray paint.
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0.4141 rounded to the nearest thousandth
Answer:
0.4141 rounded to the nearest thousandth is 0.414.
Step-by-step explanation:
Since the number is 0.4141, and the number following the thousandths place is under 5, the thousandth place stays the same. If it were 5 or over, it would round up making it 0.415, but it's not so it is 0.414.
Simplify
-(6x – 12) - (-20) – 7x
Please help me thanks
Answer:
−(6x−12)−(−20)−7x
Distribute:
=−6x+12+20+−7x
Combine Like Terms:
=−6x+12+20+−7x
=(−6x+−7x)+(12+20)
=−13x+32
Answer:
=−13x+32
what is the point-slope form of a line with slope -4 that contains the point (-2, 3)
Answer:
\(y - 3 = - 4(x + 2)\)
year 8 maths PLS help with coordinate geometry below thank you:)
Answer:
a) 6 units
b) 6 units
c) 10 units
d) 15 units
Answer: a = 6
b = 6
c = 10
d = 15
Step-by-step explanation: Use the distance formula √(x2 - x1)^2 + (y2 - y1)^2
please helpp!!!!!!!!!!
Answer:
5. Obtuse
6. Right
7. Acute
Step-by-step explanation:
5. 5,12,15
The square of the longest side is 15^2 = 225. The sum of the squares of the two shorter sides is 5^2 + 12^2 = 169. Since 169 < 225, the triangle is obtuse.
6. 6,8,10
The square of the longest side is 10^2 = 100. The sum of the squares of the two shorter sides is 6^2 + 8^2 = 100. Since 100 = 100, the triangle is right.
7. 12,10,13
The square of the longest side is 13^2 = 169. The sum of the squares of the two shorter sides is 12^2 + 10^2 = 244. Since 244 > 169, the triangle is acute.
Will you please help me with this problem
Answer:
A
Step-by-step explanation:
if you want the step by step, let me know (:
Answer:
a
Step-by-step explanation:
Identify the vertex, a of s, and y intercept: X²-x+3
Answer: vertex: (1/2,11/4)
a of s: x=1/2
y-intercept: (0,3)
Step-by-step explanation:
The ages of people who attend a local church are normally distributed. The mean age is 39.5, and the standard deviation is 18. Find the probability that a person chosen at random from this church is ages 21.5 or younger.
Answer:
15.9%.
Explanation:
The mean = 39.5
Standard deviation = 18
Raw Value, X=21.5
To find the probability that a person chosen at random from this church is ages 21.5 or younger, we first find the Z-Score.
\(\begin{gathered} Z-\text{Score}=\frac{X-\mu}{\sigma} \\ =\frac{21.5-39.5}{18} \\ =\frac{-18}{18} \\ =-1 \end{gathered}\)Next, we check the P-Value from the Z-Table.
\(P(x<21.5)=0.15866\)Therefore, the probability that a person chosen at random from this church is ages 21.5 or younger is 15.9%.
Please help me with this please and thank you
Step-by-step explanation:
what do we need to do ?
just solve the system of 2 equations ?
as we have x and -x in the equations, we simply add both equations, get one summary equation just in y, solve for y, and then use one of the original equations to solve for x :
y = x - 4
y = -x + 2
----------------
2y = 0 - 2
2y = -2
y = -1
-1 = x - 4
3 = x
x = 3
y = -1
Use the equation, 8^2x = 32^x+3 , to complete the following problems.
(a) Rewrite the equation using the same base.
(b) Solve for x. Write your answer in the simplest form.
Side note: For your answers, I ask that you show your work so that I can review it and hopefully understand how to do this myself in the future!
Answer:
Question (a)
Given equation:
\(8^{2x} = 32^{x+3}\)
8 can be written as \(2^3\)
32 can be written as \(2^5\)
Therefore, we can rewrite the equation with base 2:
\(\implies (2^3)^{2x} = (2^5)^{x+3}\)
------------------------------------------------------------------------------
Question (b)
To solve:
\((2^3)^{2x} = (2^5)^{x+3}\)
Apply the exponent rule \((a^b)^c=a^{bc}\) :
\(\implies 2^{3 \cdot 2x} = 2^{5(x+3)}\)
\(\implies 2^{6x} = 2^{5x+15}\)
\(\textsf{If }a^{f(x)}=a^{g(x)}, \textsf{ then } f(x)=g(x)\) :
\(\implies 6x = 5x+15\)
Subtract \(5x\) from both sides:
\(\implies x = 15\)
-3.7+1/4 Write your answer as a decimal to the nearest hundredth.
The answer as a decimal to the nearest hundredth is -3.45.
What is termed as the decimals?A decimal is a number with a whole as well as a fractional part. Decimal numbers are between integers but also reflect numerical value for whole plus some fraction of a whole. A decimal number has two parts: a whole number component and a fractional component. A decimal place value system is identical to the whole number value system for the entire part of a decimal number.For the given question;
The expression is given as;
= -3.7 + 1/4
Now, the fraction 1/4 can be written in decimal as 0.25.
Put the value of 1/4.
= -3.7 + 0.25
The subtraction of larger negative to smaller positive gives negative number.
= -3.45
Thus, the answer as a decimal to the nearest hundredth is -3.45.
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what function computes the value in which one-half of the data is above and one-half is below.
a. Middle
b. Mode c. average
d. Median
A leather chair has a price of $710. With sales tax, it will cost $781. What is the sales tax percentage?
Answer:
Step-by-step explanation:
Errrr....this is kind of big brain for me. also i'm new here. hope somebody else can answer you.
Answer:
the sales tax is 10%
Step-by-step explanation:
710 plus 10% is 781
if the marks of students in a class are [110,70,30,80,90,64] then what is the median of these marks?
Answer:
The Median is 75
Step-by-step explanation:
Medianmedian is the middle number in a set of given numbers
arranging in order will be
30,64,70,80,90,110
the middle numbers are 70 and 80
Median=80+70/2
=150/2
Median=75
In which table does y vary directly with x?
Read and tell me the correct answer! I will give brainliest
Please someone help me out!!!!! Bill is bying a pair of jeans that costs $20. He has to pay 5% sales tax. How much will he pay in all?
Answer:
21
Step-by-step explanation:
First determine the amount of tax
20 * .05
1
Add this to the original amount
20+1
21
He will pay 21 dollars
f(x)=1/4(x+3)+2
Determine whether the relationship being represented is linear, exponential or neither.
A.
linear
B.
exponential
C.
neither