The length of pop music songs is normally distributed with meze length of 215 seconds and a szard
deviation of 38 seconds. What percent of pop songs have lengths between three and four minutes?
(1) 48%
(3) 61%
(2) 57%
(4) 67%
58% of pop songs have lengths between three and four minutes
Z score is used to determine by how many standard deviations the raw score is above or below the mean. It is given by:
[tex]z=\frac{x-\mu}{\sigma} \\\\where\ x=raw\ score, \mu=mean,\sigma=standard \ deviation\\\\Given\ that:\\\\\mu=215,\sigma=38.\\\\For\ x=3\ min(180\ sec):\\\\z=\frac{180-215}{38}=-0.92\\\\For\ x=4\ min(240\ sec):\\\\z=\frac{240-215}{38}=0.71[/tex]
From the normal distribution table, P(180 < x < 240) = P(-0.92 < z < 0.71) = P(z < 0.71) - P(z < -0.92) = 0.7611 - 0.1788 = 0.5823 = 58%
Find out more at: https://brainly.com/question/15016913
4. Ms. Bragg is giving a test worth 100 points. The test contains a total of 40 questions. Some questions are worth 2 points and some questions are worth 4 points on the test. Write a system of equations to determine how many of each type of question are on the test. A) Define your variables. You can use any letters you want) B) Write your system of equations. (There should be 2 separate equations)
9514 1404 393
Explanation:
A)
Let t and f represent the numbers of two-point and four-point questions, respectively.
__
B) The number of points for each type of question is the product of the point-value per question and the number of questions of that type.
2t + 4f = 100 . . . . . the test is worth 100 points
t + f = 40 . . . . . . . . there are 40 questions on the test
_____
Additional comment
The test will have 30 two-point questions and 10 four-point questions.
I’m confused on this question
Answer:
[tex]\lim_{x \to 5}f(x)=-5\\\lim_{x \to 1^-} f(x)=3\\\lim_{x \to 1^+} f(x)=3\\\lim_{x \to 1} f(x)=4\\[/tex]
Step-by-step explanation:
[tex]\lim_{x \to 5}f(x)[/tex]
This means "the limit of f(x) as x approaches 5"
In this case, f(x) is a basic linear function while x > 1, so a limit is not necessary but it can still be used as it is here. For this one, you can just calculate f(5), and that is:
[tex]f(x)=5-2x[/tex]
[tex]f(5)=5-2(5)=5-10=-5[/tex]
[tex]\lim_{x \to 5}f(x)=-5[/tex]
===================
[tex]\lim_{x \to 1^-} f(x)[/tex]
This one is a little different. It means "the limit of f(x) as x approaches 1 from the negative (left) direction"
The negative direction of course means x will be less than 1, so we'll use this function:
[tex]f(x)=4-x[/tex]
It's easier if you graph it, but you can also do it like this:
[tex]f(0)=4+0=4\\f(0.5)=4-0.5=3.5\\f(0.75)=4-0.75=3.25\\f(0.9)=4-0.9=3.1\\f(0.99)=4-0.99=3.01[/tex]
There's a clear pattern there. You can see that f(1) should be 3, but this function only applies while x is less than 1 so it can never reach 3. It will get infinitely close, and that can be shown with the limit:
[tex]\lim_{x \to 1^-} f(x)=3[/tex]
===================
[tex]\lim_{x \to 1^+} f(x)[/tex]
This one works the same way, but from the positive (right) direction.
[tex]f(2)=5-4=1\\f(1.5)=5-3=2\\f(1.25)=5-2.5=2.5\\f(1.1)=5-2.2=2.8\\f(1.01)=5-2.02=2.98\\f(1.001)=5-2.002=2.998[/tex]
It will also get infinitely close to 3 when x = 1, but won't ever reach it because this function only applies when x is greater than 1.
[tex]\lim_{x \to 1^+} f(x)=3[/tex]
===================
[tex]\lim_{x \to 1} f(x)[/tex]
Here, the function for x=1 is just:
[tex]f(x)=4[/tex]
It's given already, so the limit is just:
[tex]\lim_{x \to 1} f(x)=4[/tex]
I need this done, FAST! EMERGANCY! 20 4 this!
The account balance of each of three children at the end of a month is shown below: John has −$2.75 Cheryl has −$3.00 Andrew has as much savings in his account as the amount John owes the bank. Part A: On a blank paper, draw a number line from −4 to +4. Plot points on the number line to show the account balances of the three children. Label the points using the name of each child. Describe in detail how you created and labeled this number line, and what it looks like in detail. (5 points) Part B: Determine whether John or Cheryl owes the bank more. Use absolute values and inequalities to write statements that justify your conclusion. (5 points)
Answer:John has −$2.75
Cheryl has −$3.00
Andrew has as much savings in his account as the amount John owes the bank.
: On a blank paper, draw a number line from −4 to +4. Plot points on the number line to show the account balances of the three children. Label the points using the name of each child. Describe in detail how you created and labeled this number line, and what it looks like in detail. (5 points)
: Determine whether John or Cheryl owes the bank more. Use absolute values and inequalities to write statements that justify your conclusion. (5 points)
Step-by-step explanation:
HELP i need what is 4 divided by 120000 telll me plz in tried the calculator but my parents blocked the calculator on me so plz help me
HELPPPP!!!!!!!!!!!!!!
Answer:
B
Step-by-step explanation:
125/29.35=4.409171076
4.409171076 is rounded to 4.41
Translate the English phrase into an algebraic expression: four times the difference of v and one.
Answer:
4(v-1)
Step-by-step explanation:
the answer is 4(V-1)
Answer:
the answer is 4(v-1)
Uhm is this a function?
Answer:
yes it is
Step-by-step explanation:
For exercises 7-9 write expressions for the area of each rectangle in two different ways. Then find the area using each expressions.
Answer:
No Questions are shown here
Step-by-step explanation:
Just says "For exercises, 7-9 write expressions for the area of each rectangle in two different ways. Then find the area using each expression."
please help me !
this work is due tommorow!!
ks3 year 8!
Answer:
£2578.8
Step-by-step explanation:
49×12.80= £627.2
if 49 of the people are under 16, then the rest are 16 and above
so, 155-49 = 106
number of students at 16 and above are 106
then, 106× £18.60 = £2578.8.
what is multiple integrals
Mr. Jones's prescription calls for 1.04 tablets per day. Based on this information, how many tablets should Mr. Jones take per day? a) 1.25 O b) 1.5 c) 1 O d) 2
I think the answer is a but I'm not sure I'm really a little confused I want to check with this app please can someone heelp me
i rlly need help ill give u brainliest
Answer:
A. 2^4*5 B. 3^3*2
Step-by-step explanation:
80/2 = 40
40 and 2
20 and 2
10 and 2
5 and 2
So we got 4 2's and one 5 bcz they prime.
27 and 2
9 and 3
3 and 3
So 2 3's and one 2 bcz they prime.
PLease help middle school math 40 points
Answer:
b
Step-by-step explanation:
2/5 * 2x = 4/5
2/5 * 3 = 6/5 = 1 1/5
Answer:
B.
Step-by-step explanation:
Using the distributive property (multiplying 2/5 to both 2x and 3) we can get the answer 4/5x + 1 1/5.
I hope this helps :)
Mr. Walthour is building a storage in a conical shape. The base of the shed is 4 meters in diameter and the height of the shed is 3.8 meters. What is the volume of the shed? Round to the nearest tenth.
Please help me :/!!!!
Answer:
(3, 9)
Step-by-step explanation:
Set 3x and 2x+3 equal to each other forming an equation in x.
3x=2x+3
Solve for x.
x=3
Substitute the given value of x into the equation y=3x.
y=3x3
Solve for y.
y=9
(x, y) = (3, 9)
Hope this helps :)
What is the least common denominator of
1/3 and 7/9
Answer:
9
Step-by-step explanation:
9 is the LCD. So you have to multiply 3 by 3 to get 9, so multiply the numerator (1) by 3. 3/9 is the answer to that.
Question 1 of 10
f (2) = y + 10. Find the inverse of f(x).
O A f-'(x) = (x + 10)
O B. f-1(x) = 73 + 10
O C. f-1(x) = (x – 10)3
O D. f-'(x) = x3 – 10
Option D
step by step explanation:
[tex] \sf f(x) = \sqrt[3]{x + 10} \\ \sf y = \sqrt[3]{x + 10} \\ \sf y = \sqrt[3]{y + 10} \\ \sf y = {x}^{3} - 10 \\ \sf {f}^{ - 1} (x) = {x}^{3} - 10[/tex]
The inverse of the given function is represented as f' ( x ) = x³ - 10
What is Function Rule?A function is a mathematical object that takes an input (or several inputs) and produces an output. The rule of a function describes how the input is transformed to produce the output. It can be written using mathematical notation, words, or a combination of both.
Functions are used in many areas of mathematics, science, engineering, and other fields to model relationships between variables, make predictions, and solve problems.
Given data ,
Let the function be represented as A
Now , the value of A is
Now , the function is depicted as f ( x ) = ∛( x + 10 )
Simplifying results in
The function's inverse is obtained by swapping the x and y variables.
So ,
y = ∛( x + 10 )
x = ∛( y + 10 )
On solving for y , we get
y = x³ - 10
And , the inverse is f' ( x ) = x³ - 10
The function is therefore f' (x) = x³ - 10.
Go here to read more about the function rule.
https://brainly.com/question/3760195
#SPJ7
Write an explanation to help your friend understand why the expression 0.45x represents decreasing x by 55%.
Need the answer please and thank you!
Answer:
A variable is a letter that is used to represent a number. For instance, in this problem the variable x represents an unknown number that will equal 5 when added to 2.
Step-by-step explanation:
The percentage is calculated by dividing the required value by the total value and multiplying by 100.
Required percentage value = a
total value = b
Percentage = a/b x 100
x - (55/100)x = 0.45x
The decreasing x by 55% is 0.45x
What is a percentage?
The percentage is calculated by dividing the required value by the total value and multiplying by 100.
Example:
Required percentage value = a
total value = b
Percentage = a/b x 100
Example:
50% = 50/100 = 1/2
25% = 25/100 = 1/4
20% = 20/100 = 1/5
10% = 10/100 = 1/10
We have,
Decreasing x by 55%.
This can be written as,
= x - (55/100)x
= x - 0.55x
= 0.45x
Thus,
The decreasing x by 55% is 0.45x
Learn more about percentages here:
https://brainly.com/question/11403063
#SPJ2
Need help with geometry problem
Answer:
y = [tex]6\sqrt{5}[/tex]
Step-by-step explanation:
x^2 + z^2 = 29^2
x^2 = y^2 + 9^2
y^2 + 20^2 = z^2
29^2 - z^2 = y^2 + 81 (equating for x^2 from eqn 1 and 2)
substitute 3rd eqn in 4th
29^2 - (y^2 + 20^2) = y^2 + 81
841 - y^2 - 400 = y^2 + 81
441 = 2y^2 + 81
360 = 2y^2
y^2 = 180
y = [tex]\sqrt{180}[/tex]
= [tex]\sqrt{36*5} \\[/tex]
y = [tex]6\sqrt{5}[/tex]
Nate biked 54 miles in 4 1/2 hours. What was Nate’s average speed in miles per hour.
Answer:
12mph
Step-by-step explanation:
You must divide the 54 miles by the 4 1/2 hours which will give you 12mph
The mass of Earth is approximately 6 x 10^27 that of the Sun is 330,000 times as much. The gravitational constant is 6.7 x 10^-8 cm/s2.g. The distance of Earth from the Sun is about 1.5 x 10^12 cm. Compute, approximately, the work necessary to increase the distance of Earth from the Sun by 1 cm.
Answer:
12.89
Step-by-step explanation:
ititiiitiiiuuyhgtfvnmmnhhnjijli
A carpenter used 1/3 able to finish of a box of nails while working on a birdhouse and was able to finish 1/5 of it. At this rate, how many boxes will he need to finish the entire birdhouse?
Answer:
He will need 1 and 2/3 boxes
Step-by-step explanation:
1/5= 1/3 boxes
5/5= 1/3* 5 boxes
Hope this helps!
Let me know if it does
How are commercial banks are funded?
Answer:
Commercial banks are funded through Customer deposits as well as with the fees charged against their services provided to customers. The Banks provide many services like funding to customers and many form loans, they also deposit their money.
Step-by-step explanation:
this is the correct answer happy
Answer:
CUSTOMER DEPOSITS
Step-by-step explanation:
CORRECT VIA EDMENTUM 2022
what number is its own oppositie?
Answer:
0Step-by-step explanation:
what number is its own oppositie?
The number 0 is the only number that is its own opposite.
Find the additive inverse and the multiplicative inverse, if it exists, of the given number. 5 in modulo 8 arithmetic
The additive inverse of 5 modulo 8 is the number a such that
5 + a ≡ 0 (mod 8)
Then
a ≡ -5 ≡ -5 + 8 ≡ 3 (mod 8)
The multiplicative inverse is m such that
5m ≡ 1 (mod 8)
Use the Euclidean algorithm:
8 = 1•5 + 3
5 = 1•3 + 2
3 = 1•2 + 1
Then
1 = 3 - 1•2
1 = 3 - 1•(5 - 1•3) = 2•3 - 1•5
1 = 2•(8 - 1•5) - 1•5 = 2•8 - 3•5
and so
1 ≡ 2•8 - 3•5 ≡ (-3)•5 (mod 8)
which means the inverse of 5 is
-3 ≡ 8 - 3 ≡ 5 (mod 8)
A couple stayed for 3 years before having their first child. then 2 years before the second. 2 years again before the third, and so on until the sixth child. If the husband was 28 years and the wife was 25 years when they had their first child, what is the sum of the ages of the couple a year before the last born?
Answer:
71
Step-by-step explanation:
25+2+2+2+2+1=34
28+2+2+2+2+1=37
sum=34+37
71
Answer:
3+2+2=7 year back
28-7=21
25-7=18
years old pls mark me as brainlist
Jonas is conducting an experiment using a 10-sided die. He determines that the theoretical probability of rolling a 3 is StartFraction 1 over 10 EndFraction. He rolls the die 20 times. Four of those rolls result in a 3. Which adjustment can Jonas make to his experiment so the theoretical and experimental probabilities are likely to be closer?
A.He can decrease the sample space.
B.He can increase the sample space.
C.He can decrease the number of trials.
D.He can increase the number of trials.
Answer:
A. He can decrease the simple spacw
Answer:
D. He can increase the number of trials
Can someone please walk me through these 2 problems? I'm using the formula that the problem states but I have to be going wrong somewhere because all of my answers have been incorrect. The correct answers are below, but I have no idea how to get to them.
35: -13 - 34j volts
37: 28 + 57j volts
[tex]\boxed{35}~~ \begin{cases} I=2-7j\\ Z=4-3j \end{cases}\implies E=(2-7j)(4-3j) \\\\\\ \begin{array}{rllll} 4-3j\\ \times ~\hfill 2\\[-0.5em] \hrulefill\\ 8-6j \end{array}~~+ ~~ \begin{array}{rllll} 4-3j\\ \times ~\hfill -7j\\[-0.5em] \hrulefill\\ -28j+21j^2 \end{array}\qquad \implies 8-6j-28j+21j^2 \\\\[-0.35em] ~\dotfill\\\\ ~\hfill E=21j^2-34j+8~\hfill[/tex]
[tex]\boxed{36}~~ \begin{cases} I=3+10j\\ Z=6-j \end{cases}\implies E=(3+10j)(6-j) \\\\\\ \begin{array}{rllll} 6-j\\ \times ~\hfill 3\\[-0.5em] \hrulefill\\ 18-3j \end{array}~~+ ~~ \begin{array}{rllll} 6-j\\ \times ~\hfill 10j\\[-0.5em] \hrulefill\\ 60j-10j^2 \end{array}\qquad \implies 18-3j+60j-10j^2 \\\\[-0.35em] ~\dotfill\\\\ ~\hfill E=-10j^2+57j+18~\hfill[/tex]
A map has a scale of 1 cm to 20km. Rewrite the scale as a ration in its simplest form.
BRAINLIEST HELP PLS !!!!!
Answer:
1 : 2000000
Step-by-step explanation:
we have to convert 20km into cm so
20km×100000
=2000000
So ratio is 1:2000000
MARK ME BRAINLIEST PLS!Answer:
1:2000000.
Step-by-step explanation:
1 km = 1000m = 100*1000
= 100,000 cm
20 km = 2,000,000 cm.