Answer:
She walks back for 4.2 hours
Step-by-step explanation:
Notice that we don't know the distance of the race (so let's name it "d").
She clearly would spend less time running (t1) the distance d at 7 mph, than when coming back walking (t2) at 3 mph.
But we know that the addition of both times must be 6 hours which is what she has to spend:
t1 + t2 = 6
Considering the equation that relates distance (D), time(t) , and speed (v) as:
v = D/t
we can solve for the times t1 and t2 in each trip (running vs walking){
t1 = d/7
t2 = d/3
then when we add these two equations term by term, we get:
t1 + t2 = d/7 + d/3
extract d common factor;
t1 + t2 = d (1/7 + 1/3)
replace t1 + t2 with the 6 hours:
6 = d (10/21)
multiply both sides by 21, and divide both sides by 10 to isolate d:
21 * 6 / 10 = d
d = 12.6 miles
Now knowing the distance she run and walked, we can find the time she spent walking back (t2)
t2 = 12.6 /3 = 4.2 hours
How do we write equations from word problems?
PLS HELP WITH QUESTION 5. I’m being timed
help please! look at question
A particular employee arrives at work sometime between 8:00 a.m. and 8:30 a.m. Based on past experience the company has determined that the employee is equally likely to arrive at any time between 8:00 a.m. and 8:30 a.m. Find the probability that the employee will arrive between 8:15 a.m. and 8:25 a.m. Round your answer to four decimal places, if necessary.
Answer:
0.3333 = 33.33% probability that the employee will arrive between 8:15 a.m. and 8:25 a.m.
Step-by-step explanation:
A distribution is called uniform if each outcome has the same probability of happening.
The uniform distributon has two bounds, a and b, and the probability of finding a value between c and d is given by:
[tex]P(c \leq X \leq d) = \frac{d - c}{b - a}[/tex]
A particular employee arrives at work sometime between 8:00 a.m. and 8:30 a.m.
We can consider 8 am = 0, and 8:30 am = 30, so [tex]a = 0, b = 30[/tex]
Find the probability that the employee will arrive between 8:15 a.m. and 8:25 a.m.
Between 15 and 25, so:
[tex]P(15 \leq X \leq 25) = \frac{25 - 15}{30 - 0} = 0.3333[/tex]
0.3333 = 33.33% probability that the employee will arrive between 8:15 a.m. and 8:25 a.m.
Ava borrows $600 to buy a bike at a yearly simple interest rate of 2.25%. Ava borrows the money for 3 years. How much does Ava pay in simple interest?
Answer:
40.50
Step-by-step explanation:
you take 600.00 and multiply it by 2.25 you will get 1,350 divide 1,350 by 100 you will get 13.50 multiply 13.50 times 3 you get 40.50 that is interest for 3 years
Given that f(x) = 2x - 5, find the value of x that makes f(x) = 15.
а
5
b
10
20
Od
25
Answer:
When x=10 f(x) is equal to 15
Step-by-step explanation:
Just substitute the two equations, 15=2x-5 -> 20=2x -> x=10.
The length of a rectangular rug is 4 less than twice its width. The perimeter of the rug is 40 feet. What is the area of the rug?
1) 96 sq ft
2) 56 sq ft
3) 104 sq ft
4) 86 sq ft
slope
y intercept
x intercept
Answer:
Step-by-step explanation:
y = mx + b
Here, m is the slope.
b is the y-intercept
x-intercept = -b/m
y = 3x -4
a) slope = 3
b) y-intercept = (-4)
c) x -intercept = -(-4)/3 = 4/3
[tex]y = \frac{1}{5}x-3[/tex]
a) slope = [tex]\frac{1}{5}[/tex]
b) y-intercept = (-3)
c) x -intercept = [tex]-\frac{1}{5}[/tex]÷(-3)
[tex]= \frac{-1}{5}*\frac{-1}{3}\\\\=\frac{1}{15}[/tex]
You sell 300 shares of Dendreon Corp at $8.89. You purchased the stock at $42.87. How much money did you lose?
O $42.87
O $8.89
$2,667
O $10,194
$12,861
Jasmine ran 5 miles in 42 minutes.
Part A
At what rate did Jasmine run?
Jasmine ran at a rate of
minutes per mile.
Question 2
Part B
Katie ran 4 miles. She ran at a rate that was 1.1 minutes per mile slower than Jasmine. For how many minutes did Katie run? Explain how you determined your answer.
HELPPPPPPPP.
) The National Assessment of Educational Progress (NAEP) gave a test of basic arithmetic and the ability to apply it in everyday life to a sample of 840 men 21 to 25 years of age. Scores range from 0 to 500; for example, someone with a score of 325 can determine the price of a meal from a menu. The mean score for these 840 young men was x⎯⎯⎯ = 272. We want to estimate the mean score μ in the population of all young men. Consider the NAEP sample as an SRS from a Normal population with standard deviation σ = 60. (a) If we take many samples, the sample mean x⎯⎯⎯ varies from sample to sample according to a Normal distribution with mean equal to the unknown mean score μ in the population. What is the standard deviation of this sampling distribution? (b) According to the 95 part of the 68-95-99.7 rule, 95% of all values of x⎯⎯⎯ fall within _______ on either side of the unknown mean μ. What is the missing number? (c) What is the 95% confidence interval for the population mean score μ based on this one sample? Note: Use the 68-95-99.7 rule to find the interval.
Answer:
a) The standard deviation of this sampling distribution is 2.07.
b) The missing number is 4.14.
c) The 95% confidence interval for the population mean score μ based on this one sample is between 267.86 and 276.14.
Step-by-step explanation:
To solve this question, we need to understand the Empirical Rule and the Central Limit Theorem.
Empirical Rule:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
Central Limit Theorem:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
In this question:
[tex]\mu = 272, n = 840, \sigma = 60[/tex]
(a) If we take many samples, the sample mean x⎯⎯⎯ varies from sample to sample according to a Normal distribution with mean equal to the unknown mean score μ in the population. What is the standard deviation of this sampling distribution?
Using the Central Limit Theorem:
[tex]s = \frac{\sigma}{\sqrt{n}} = \frac{60}{\sqrt{840}} = 2.07[/tex]
The standard deviation of this sampling distribution is 2.07.
(b) According to the 95 part of the 68-95-99.7 rule, 95% of all values of x⎯⎯⎯ fall within _______ on either side of the unknown mean μ. What is the missing number?
Within 2 standard deviations of the mean.
So, 2*2.07 = 4.14
The missing number is 4.14.
(c) What is the 95% confidence interval for the population mean score μ based on this one sample?
Within 4.14 of the mean
272 - 4.14 = 267.86
272 + 4.14 = 276.14
The 95% confidence interval for the population mean score μ based on this one sample is between 267.86 and 276.14.
Natalie wants to know how much money her computer costs each day if she never turns it off. She uses a meter to record the amount of energy her computer uses each day for 30 days. After recording the cost for 30 days, she determined the cost to run her computer is equal to the function /(d), where f(d) = 0.40d, where d is the number of days What is the value of '(d) at f(30)? dollars 4. What is the value of f(30) in context? I Running a computer for 30 days will cost her $ in electricity.
Answer:
Step-by-step explanation:
f(30) = 0.40×30 = $12
Running the computer for 30 days will cost $12 in electricity.
can u pls help me with this question 2
find the difference 4 1/3 - 2 2/3
Answer:
1 2/3
Step-by-step explanation:
convert to improper fraction:
13/3 - 8/3
then solve:
13/3 - 8/3 = 5/3
convert back to a mixed number (unless your not supposed to, if that is the case then "5/3" is your answer):
"1 2/3" is "5/3" as a mixed number.
so your answer (as a mixed number) is:
"1 2/3"
Two cities are approximately 350 miles apart on the surface of the earth. Assuming that the radius of the earth is 4,000 miles, find the radian measure of the central angle with its vertex at the center of the earth that has one city on one side and another one on the other side. a. 0.0775 radians b. 0.1025 radians c. 0.0875 radians d. 0.0825 radians e. 0.1075 radians ____ 6. Name the reference angle in both degrees and radians.
Answer:
[tex]\mathbf{\theta = 0.0875 \ radians}[/tex]
Step-by-step explanation:
Given that:
The distance between city A and city B = 350 miles; &
The radius of the earth = 4000 miles
We all know that:
l = rθ
[tex]\theta = \dfrac{l}{r}[/tex]
[tex]\theta = \dfrac{350}{4000}[/tex]
[tex]\mathbf{\theta = 0.0875 \ radians}[/tex]
From l = rθ; recall that l = a
so;
a = rθ
350 = 4000×θ
θ = 350/4000
θ = 35/400 degree
In radians;
θ = (35/400) × (π/180)
θ = (7π /800× 180) radians
I need help with this question
The RideEm Bicycles factory can produce 100 bicycles in a day at a total cost of $10,900, and it can produce 120 bicycles in a day at a total cost of $11,700. (a) Find a linear function that models the total cost for RideEm to produce x bicycles.
Answer:
c(x) = 40 (x) + $6,900
Step-by-step explanation:
According to the scenario, given data are as follows,
Total cost of 100 bicycles (x1) = $10,900
Total cost of 120 bicycles (x2) = $11,700
Let Number of bicycles = X
Than cost of X bicycles = c(X)
let, fixed cost be F and variables cost be V, than
c(X) = V(X) + F
So, we can calculate variable cost by using following method,
V = c(x2) - c(x1) ÷ ( x2 - x1)
= ( $11,700 - $10,900) ÷ ( 120 - 100)
= $800 ÷ 20
= $40
So, calculate fixed cast by putting value to equation,
$10,900 = ($40 ×100) + F
F = $10,900 - $4,000 = $6,900
So, For x number of bicycles, cost equation will be,
c(x) = 40 (x) + $6,900
Calculate a point estimate of the mean oxide thickness for all wafers in the population. (Round your answer to 3 decimal places.) (b) Calculate a point estimate of the standard deviation of oxide thickness for all wafers in the population. (Round your answer to 2 decimal places.) (c) Calculate the standard error of the point estimate from part (a). (Round your answer to 2 decimal places.)
This question is incomplete, the complete question is;
Data on oxide thickness of semiconductors are as follows: 425, 430, 414, 419, 421, 436, 418, 412, 430, 434, 423, 426, 408, 437, 435, 428, 412, 426, 409, 439, 422, 426, 414, 416
(a) Calculate a point estimate of the mean oxide thickness for all wafers in the population. (Round your answer to 3 decimal places.)
(b) Calculate a point estimate of the standard deviation of oxide thickness for all wafers in the population. (Round your answer to 2 decimal places.)
(c) Calculate the standard error of the point estimate from part (a). (Round your answer to 2 decimal places.)
Answer:
a) point estimate of the mean oxide thickness for all wafers in the population is 423.333
b) point estimate of the standard deviation of oxide thickness for all wafers in the population is 9.23
c) the standard error of the point estimate from part (a) is 1.88
Step-by-step explanation:
Given the data in the question;
x = 425, 430, 414, 419, 421, 436, 418, 412, 430, 434, 423, 426, 408, 437, 435, 428, 412, 426, 409, 439, 422, 426, 414, 416.
a)
To determine the mean;
we sum the total value divided by the sample size.
mean x" = (425 + 430 + 414 + 419 + ............... + 414 + 416) / 24
mean x'' = 10160/ 24
mean x" = 423.3333 ≈ 423.333
Therefore; point estimate of the mean oxide thickness for all wafers in the population is 423.333
b) standard deviation
we can determine the population standard deviation us the formula;
S.D(X) = √[ (ⁿ∑_[tex]_{i=1}[/tex] ([tex]X_{i}[/tex] - X")²) / n ]
= √[ {(425-423.3333)² + (430-423.3333)² +......+ (416-423.3333)² } / 24 ]
= √[ 1957.333 / 24 )
S.D(X) = 9.03
Note, the point of estimate of the variance population is biased estimate.
The unbiased point estimate of oxide thickness for all wafers in the population will be;
S.D(X) = √[ (ⁿ∑_[tex]_{i=1}[/tex] ([tex]X_{i}[/tex] - X")²) / (n-1) ]
= √[ {(425-423.3333)² + (430-423.3333)² +......+ (416-423.3333)² } / (24-1) ]
= √[ 1957.333 / 23 )
S.D(X) = 9.225 ≈ 9.23
Therefore, point estimate of the standard deviation of oxide thickness for all wafers in the population is 9.23
c) the standard error
SE (X") = S.D / √n
since the standard deviation is the unbiased estimate for the population, so;
SE (X") = 9.23 / √24
SE (X") = 1.884 ≈ 1.88
Therefore, the standard error of the point estimate from part (a) is 1.88
Construct a triangle with side lengths 6,6 and 6. what are the angle measures of a triangle
Answer:
60 degrees
Step-by-step explanation:
Hello! The side lengths of this triangle are all the same, so this is an equilateral triangle. These types of triangles have equal angles. A triangle equals 180 degrees so divide that by three. Each angle in this triangle is 60 degrees. Hope this helps :)
James bought a television that was on sale for 3/4 of the original price, the original price was 749.99 what was the sale price in dollars of the tv round your answer to the nearest cent
Find the slope of the line that contains the following pair of points: (1, 2), (5,2).
O A. - 1
O B. o
O C. 4
OD. Undefined
Answer:
The answer is 0
Step-by-step explanation:
input into slope formula
The slope of the line is 0.
The correct option is (B).
What is Slope?A line's slope is determined by how its y coordinate changes in relation to how its x coordinate changes. y and x are the net changes in the y and x coordinates, respectively. Therefore, it is possible to write the change in y coordinate with respect to the change in x coordinate as,
m = Δy/Δx where, m is the slope
Given:
Points from the graph (1, 2) and (5, 2).
So, the slope of line
= ( 2- 2) / (5 -1)
= 0 / 4
= 0
Hence, the slope of line is 0.
Learn more about slope here:
https://brainly.com/question/3605446
#SPJ2
PLEASE HELP
Betty has a piece of ribbon that is 33 feet. How can she cut it into pieces without
wasting any? Select all that apply.
A. She can cut 4 pieces that are 8.25 feet each.
LA
B. She can cut 5 pieces that are 6.6 feet each.
ock
C. She can cut 4 pieces that are 8 feet each.
4
-
D. She can cut 5 pieces that are 6.75 feet each.
Answer:
Step-by-step explanation:
A. She can cut 4 pieces that are 8.25 feet each. This uses all 33 feet of ribbon with no waste.
B. She can cut 5 pieces that are 6.6 feet each. This uses all 33 feet of ribbon with no waste.
C. She can cut 4 pieces that are 8 feet each. This adds up to 32 feet, and so 1 ft is wasted
D. She can cut 5 pieces that are 6.75 feet each. Not possible, as this adds up to 33.75 ft, which is more ribbon than Betty has.
Christian gets $100 from his Grandma for his birthday. He decides to go to the bank and put it in a
savings account which earns 1% simple interest. When he graduates high school in 6 years, how
much money will be in his account?
$100
$160
$106
$6
Answer:
6 im pretty sure
Step-by-step explanation:
...
Which is NOT equivalent to 40/100
A: 4/10
B:8/20
C:40/10
D:20/50
Answer:
B
Step-by-step explanation:
because B is 8/20 and it's not equivalent to 40/100
Find the x intercept and the y intercept of the line below.
Answer:
x=-2 y=4
the line hits both -2 on the x asis and 4 on the y
please help. I can't find answer.
Answer:
-1,5
Step-by-step explanation:
in the coordinate plane what is the length of the line segment that connects points at (4, -1) and (9, 7) round to the nearest tenth
PLEASE HELPPPPP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!! 0__________________________________________________________________0
Answer:
the answer is 9.4
Step-by-step explanation:
We get that formula is:
d=[tex]\sqrt{(9-4)^{2} +(7--1)^{2} }=\sqrt{89}=9.4339[/tex]
The perimeter of a rectangular field is 580 yards. The length is 30 yards more than the width. Find the length and width of the field (in yards).
2 L + 2 W = 580
W = L - 30
2( L - 30) + 2 L =580
2L - 60 + 2 L =580
4 L = 640
L = 160
W = 160-30= 130
160 × 2 + 130 × 2 = 580
Is 6/10 more than 3/4
Answer:
3/4 is greater
Step-by-step explanation:
3/4 > 6/10
Answer:
3/4 is more
Step-by-step explanation:
divide 6/10 by 2 to get a simpler fraction. that will be 3/5. to make 3/5 and 3/4 have a common denominator you need to multiply 3/5 by 4 which is 12/20, then 3/4 by 5 which is 15/20.
A bottling company produces bottles that hold 10 ounces of liquid. Periodically, the company gets complaints that their bottles are not holding enough liquid. To test this claim, the bottling company randomly samples 64 bottles and finds the average amount of liquid held by the bottles is 9.9145 ounces with a standard deviation of 0.40 ounce. Suppose the p-value of this test is 0.0436. State the proper conclusion. choose from below and explain why.
A) At α = 0.05, reject the null hypothesis.
B) At α = 0.10, fail to reject the null hypothesis.
C) At α = 0.025, reject the null hypothesis.
D) At α = 0.05, accept the null hypothesis.
Answer:
A) At α = 0.05, reject the null hypothesis.
Step-by-step explanation:
Given a p-test value of 0.0436 ;
P-value = 0.0436
Recall :
Decision region :
Reject Null if p value < α
Testing the options :
A) At α = 0.05,
0.0436 < 0.05 (true)
Since p value < α ; Reject the null hypothesis.
B) At α = 0.10,
0.0436 < 0.1
True conclusion is to reject the Null Hypothesis
Hence, option B is incorrect.
C) At α = 0.025, reject the null hypothesis.
0.0436 > 0.025
True conclusion is ; Fail to reject the Null ;
Hence, option C is incorrect
D) At α = 0.05, accept the null hypothesis.
0.0436 < 0.05
True conclusion is ; reject the Null
Hence, option D is incorrect