Answer:
Step-by-step explanation:
f(x) = x² is an up-opening parabola with vertex (0,0). There is one x-intercept, and that is the vertex.
g(x) = x²-7 is the equivalent to f(x) shifted down 7 units. Since the vertex is below the x-axis and the parabola opens upwards, it intercepts the x-axis at two points.
if the circumference of a circle is 52 cm, what is the radius? round to the nearest tenth. PLESE HELP I DONT HAVE THAT MUCH TIME :(
Answer:
8.3
Step-by-step explanation:
Given,
Circumference of the circle = 52 cm
Therefore ,
By the problem,
[tex] = > 2\pi r = 52[/tex]
[tex] = > 2 \times 3.14 \times r = 52[/tex]
[tex] = > r = \frac{52}{3.14 \times 2} [/tex]
=> r = 8.2802547771
Rounded to nearest tenth,
=> r = 8.3 (Ans)
Find the value of 5⁰ X 7⁰ X 3⁰
plz help asap
Answer:
5⁰ × 7⁰ × 3⁰ = 1
Step-by-step explanation:
5⁰ × 7⁰ × 3⁰ = ?
5⁰ = 1
7⁰ = 1
3⁰ = 1
1 × 1 × 1 = 1
The distance around the outside of an apartment is 0.3 mile. Keira ran 0.1 of the distance during her lunch. How far did she run?
Answer:
0.1
Step-by-step explanation:
In ΔVWX, x = 9.1 inches, w = 5.4 inches and ∠W=161°. Find all possible values of ∠X, to the nearest 10th of a degree
Answer:
NO POSSIBLE TRIANGLES
Step-by-step explanation:
Answer:
no possible triangles
Step-by-step explanation:
What is the value of the expression below when x=7?
6x+ 10
A. 52
B. 67
C. 42
D.77
Answer:
52
Step-by-step explanation:
when a letter is next to a number like that and they tell u what the letter is u times it so 6x7+10=52 hope this helped :P
Write the quadratic equation in standard form.
- 4(x - x²) = 8
Determine if the quadratic function
Answer:
x² - x - 2 = 0
Step-by-step explanation:
Given:
- 4(x - x²) = 8
Find:
Standards form
Computation:
- 4(x - x²) = 8
(x - x²) = -2
x - x² = -2
x² - x - 2 = 0
g The average midterm score of students in a certain course is 70 points. From the past experience it is known that the midterm scores in this course are Normally distributed. If 29 students are randomly selected and the standard deviation of their scores is found to be 13.15 points, find the probability that the average midterm score of these students is at most 75 points. (Round your final answer to 3 places after the decimal point).
Answer:
0.98 = 98% probability that the average midterm score of these students is at most 75 points.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
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.
The average midterm score of students in a certain course is 70 points.
This means that [tex]\mu = 70[/tex]
29 students are randomly selected and the standard deviation of their scores is found to be 13.15 points.
This means that [tex]\sigma = 13.15, n = 29, s = \frac{13.15}{\sqrt{29}} = 2.44[/tex]
Find the probability that the average midterm score of these students is at most 75 points.
This is the pvalue of Z when X = 75. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{75 - 70}{2.44}[/tex]
[tex]Z = 2.05[/tex]
[tex]Z = 2.05[/tex] has a pvalue of 0.98.
0.98 = 98% probability that the average midterm score of these students is at most 75 points.
the measures of the angles of a triangle are shown in the figure below. solve for x
Answer:
Brainliest????
Step-by-step explanation:
X=23°
Branliest to correct answer explain how you solved it please
Answer:
0.03
Step-by-step explanation:
.25% for the tails times .5 for the odd number on the dice times 0.25 for the clubs because it is a 13/52 chance you will pull a clubs and put that all together and you get 0.03125 simplified and you get 0.03
Answer:
0.03
Step-by-step explanation:
The probability of landing on 1 tail is 1/2, since it is 1 out of 2 options, a tail or a head. If you want the probability of two tails, it would be 1/2 * 1/2 = 1/4.
Next we can take the probability of rolling an odd number on a fair die. A fair die has 3 even numbers: 2,4,6; and 3 odd numbers: 1,3,5. Since 3/6 or 1/2 of the numbers are odd, there is a 50% chance that it would roll an odd number.
Finally, drawing a club out of standard deck of cards is 1/4, since there are 4 choices: hearts, spades, clubs, or diamonds. You now get the idea, and you can figure out that the probability would be 1/4.
Our last step is to multiply all the answers we get, since to get all of them at once would lower your chances. 1/4 * 1/2 * 1/4 = 1/32 = 0.03125; rounded to 0.03.
Q1. If sinθ = 3/5 and cosθ = 4/5, Find the value of tanθ (Use Pythagorean Identity)
Q2. If sinθ = 3/5 and cosθ = 4/5, Find the value of tanθ (Use Trignometric Identity)
Step-by-step explanation:
[tex]sinθ = \frac{3}{5} \: \: cosθ = \frac{4}{5} \\ now \\ tanθ = \frac{sinθ}{cos θ } \\ = \frac{3}{5 } \div \frac{4}{5} \\ = \frac{3}{5} \times \frac{5}{4} \\ = \frac{3}{4} [/tex]
Hope it will help :)❤
Can y’all help me on question 27?!
Answer:
B and D
Step-by-step explanation:
A would be:
57 + 2j
C would be:
13-t
The mean monthly water bill for 44 residents of the local apartment complex is $104. What is the best point estimate for the mean monthly water bill for all residents of the local apartment complex?
Answer:
$104
Step-by-step explanation:
The computation of the best point estimate for the mean monthly water bill is shown below:
Given that
The mean monthly water bill is $104
and, the number of residents is 44
based on the above information
The best point estimate would be equivalent to the mean monthly water bill i.e. $104
hence, the same would be considered
Please answer this :/
Answer:
-60
Step-by-step explanation:
-45+s=-105
s=-105+45
s=-60
Help please!!!!!! I don't have a lot of time
Answer:
Its 5,...................
Answer:
5
Step-by-step explanation:
simplify the exponent
35/8-1
simplify
35/7
simplify
5
Suppose that a committee is studying whether there is waste of time in our judicial system. It is interested in the mean amount of time individuals waste at the courthouse waiting to be called for jury duty. The committee randomly surveyed 81 people who recently served as jurors. The sample mean wait time was eight hours with a sample standard deviation of four hours. Construct a 95% confidence interval for the population mean time wasted. Which distribution should you use for this problem
Answer:
The t-distribution is used, as we have the standard deviation of the sample.
The 95% confidence interval for the population mean time wasted is between 7.12 hours and 8.88 hours.
Step-by-step explanation:
We have the standard deviation for the sample, which meas that the t-distribution should be used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 81 - 1 = 80
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 80 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 1.99
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 1.99\frac{4}{\sqrt{81}} = 0.88[/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 8 - 0.88 = 7.12 hours.
The upper end of the interval is the sample mean added to M. So it is 8 + 0.88 = 8.88 hours.
The 95% confidence interval for the population mean time wasted is between 7.12 hours and 8.88 hours.
i need help ////////
Answer:
[tex]1\frac{1}{2}[/tex] miles = 7920 feet
2[tex]\frac{1}{2}[/tex] miles = 13200 feet
3[tex]\frac{1}{2}[/tex] miles = 18480 feet
4[tex]\frac{1}{2}[/tex] miles = 23760 feet
5[tex]\frac{1}{2}[/tex] miles = 29040 feet
6[tex]\frac{1}{2}[/tex] miles = 34320 feet
Explanation:
1 mile = 5280 feet
[tex]\frac{1}{2}[/tex] miles = 2640 feet
to convert miles into feet, multiply the whole numbers by 5280 and add 2640 to find your overall feet
2[tex]\frac{1}{2}[/tex] : 2 x 5280 + 2640 = 13200 ft
3[tex]\frac{1}{2}[/tex] : 3 x 5280 + 2640 = 18480 ft
4[tex]\frac{1}{2}[/tex] : 4 x 5280 + 2640 = 23760 ft
5[tex]\frac{1}{2}[/tex] : 5 x 5280 + 2640 = 29040 ft
6[tex]\frac{1}{2}[/tex] : 6 x 5280 + 2640 = 34320 ft
Please let me know asap
Answer:
100
Step-by-step explanation:
Hello There!
∠4 and ∠8 are corresponding angles
corresponding angles are congruent so if ∠4 = 100 then ∠8 also equals 100
a normal distribution has a mean of 56 and a standard deviation of 8. Find the percentage of data values that are in the given interval. Use the curve to aid you.
Answer:
12) Between 40 and 64 = 0.815
13) Between 32 and 40 = 0.0235
14) Between 56 and 64 = 0.34
15) At most 56 = 0.515
16) At least 72 = 0.025
17) At most 64 = 0.855
Explanation:
To answer this, we will convert each of the values into their standardized form to make this easier.
The standardized score for any value is the value minus the mean then divided by the standard deviation.
z = (x - μ)/σ
x = Each value
μ = Mean = 56
σ = Standard deviation = 8
12) Between 40 and 64
For 40,
z = (x - μ)/σ = (40 - 56)/8 = (-16/8) = -2
For 64
z = (x - μ)/σ = (64 - 56)/8 = (8/8) = 1
So,
Between 40 and 64 = Between -2 and 1
From the curve, noting that the central point is the mean, with standard score of 0, the lines before it move in step of 1 standard deviation towards the negative side, that is, -1, -2, etc. And the lines before the central point move towards the positive side, that is, 1, 2, 3, etc.
So,
Between -2 and 1 = 0.135 + 0.34 + 0.34 = 0.815
13) Between 32 and 40
For 32,
z = (x - μ)/σ = (32 - 56)/8 = (-24/8) = -3
For 40,
z = (x - μ)/σ = (40 - 56)/8 = (-16/8) = -2
So,
Between 32 and 40 = Between -3 and -2 = 0.0235
14) Between 56 and 64
For 56,
z = (x - μ)/σ = (56 - 56)/8 = (0/8) = 0
For 64,
z = (x - μ)/σ = (64 - 56)/8 = (8/8) = 1
Between 56 and 64 = Between 0 and 1 = 0.34
15) At most 56
For 56,
z = (x - μ)/σ = (56 - 56)/8 = (0/8) = 0
At most 56 = At most 0 = 0.0015 + 0.0235 + 0.15 + 0.34 = 0.515
All the regions before z = 0)
16) At least 72
For 72,
z = (x - μ)/σ = (72 - 56)/8 = (16/8) = 2
At least 72 = At least 2 = 0.0235 + 0.0015 = 0.025
(All the regions from z = 2 to the end)
17) At most 64
For 64,
z = (x - μ)/σ = (64 - 56)/8 = (8/8) = 1
At most 64 = At most 1 = 0.0015 + 0.0235 + 0.15 + 0.34 + 0.34 = 0.855
(All the regions before z = 1)
Hope this Helps!!!
Which would be a good estimate for the tax on $97.95 if the tax is 9.5%?
$12
$10.50
$10
$8.50
can somebody help me solve for x.
Answer:
8/3
Step-by-step explanation:
x : 4 = 4 : 6
x = 16/ 6
x = 8/3
HELP PLEASE BRAINLYIST
Examine the diagram. It is not drawn to scale.
Wh at is the m angle 3?
Х
m angle 3=
Answer:
isn't it just 50°
Step-by-step explanation:
180=a straight line.
you are given 75° and 55°
75+55=130
180-130
Answer:
105
Step-by-step explanation:
Chupapi
Some loser deleted my answers
That's why it says 1 answer and 1.5k people helped
The length of stay at a specific emergency department in Phoenix, Arizona, in 2009 had a mean of 4.6 hours with a standard deviation of 2.9. Assume that the length of stay is normally distributed.
a. What is the probability of a length of stay greater than 10 hours?
b. What length of stay is exceeded by 25% of the visits?
c. From the normally distributed model, what is the probability of a length of stay less than 0 hours? Comment on the normally distributed assumption in this example.
Answer:
a) the probability of a length of stay greater than 10 hours is 0.03144
b) the length of stay is exceeded by 25% of the visits is 6.5 hrs
c)
P( X < 0 ) = 0.0559
The probability of length of stay less than 0 hours is 0.0559, length of stay cannot be less than 0. When the normal model is used, we assume that the LOF is approximately normally distributed.
The LOF is better modeled by the normal distribution near the mean and worse in the tails.
The probabilities in the left tail for the vales of X < 0 can be neglected.
Step-by-step explanation:
Given that;
mean μ = 4.6
standard deviation σ = 2.9
let x represent length of stay;
a. What is the probability of a length of stay greater than 10 hours?
p( x > 10 ) = p( x-μ/σ > 10-4.6 / 2.9 )
= p( Z > 1.86)
= P( Z < - 1.86 )
FROM THE Z SCORE TABLE;( Z < - 1.86 ) = 0.03144
p( x > 10 ) = 0.03144
Therefore, the probability of a length of stay greater than 10 hours is 0.03144
b) What length of stay is exceeded by 25% of the visits?
p( X > x ) = 0.25
so
p( X < x ) = 0.75
p( x-μ/σ < x-4.6 / 2.9 ) = 75
p( Z < x-4.6 / 2.9 ) = 0.75 ----- 1
also, from the standard normal table; P( Z < 0.67 ) = 0.75 ------ 11
from equation 1 and 11
x-4.6 / 2.9 = 0.67
x-4.6 = 2.9 × 0.67
x - 4.6 = 1.943
x = 4.6 + 1.943
x = 6.543 ≈ 6.5
Therefore, the length of stay is exceeded by 25% of the visits is 6.5 hrs
c) From the normally distributed model, what is the probability of a length of stay less than 0 hours?
P( X < 0 ) = p( x-μ/σ < 0-4.6 / 2.9 )
= P( Z - 1.59)
from table;( Z - 1.59) = 0.0559
P( X < 0 ) = 0.0559
The probability of length of stay less than 0 hours is 0.0559, length of stay cannot be less than 0. When the normal model is used, we assume that the LOF is approximately normally distributed.
The LOF is better modeled by the normal distribution near the mean and worse in the tails.
The probabilities in the left tail for the vales of X < 0 can be neglected.
A farmer knows that a grocery store will reject a shipment of his vegetables if more than 4% of the vegetables contain blemishes. He inspects a large truckload of tomatoes to determine if the proportion with blemishes (p) exceeds 0.04. He selects an SRS of 150 tomatoes from the more than 2,000 tomatoes in the truck. Suppose that 8 tomatoes sampled are found to have blemishes. Which of the assumptions for inference about a proportion is violated, if any?
a. Large Counts: np > 10
b. Large Counts: n(1 – p) > 10
c. The sample is a random sample of the entire population.
d. 10% condition: the sample size is less than 10% of the population.
e. There do not appear to be any violations.
Answer:
Assumption A is violated
Step-by-step explanation:
x = number of blemishes = 8
n = sample size = 150
proportion = x/n = 8/150 = 0.0533
1. large counts: np> 10
= 150 * 0.0533 >10
= 7.995 > 10
this assumpton is obviously violated. 7.995 is not greater than 10
2. Large Counts: n(1 - p) > 10
150(1-0.0533)>10
150-7.995 > 10
142.005> 10
there is no violation. The assumption is satisfied
3. This assumption is satisfied. this is because the tomatoes were selected using simple random sampling.
4. 10% of the population = 0.1 * 2000 = 200
the sample size = 150
150 < 200
this assumption is satisfied
A cone in the diagram below has a radius (r) of 10mm and its height (h) is 24mm calculate the length of the slant height
Answer:
26mm
Step-by-step explanation:
by the Pythagorean theorem,
[tex]x^2=10^2+24^2\\x^2=676\\x=26[/tex]
28.
Car A and car B are 120 km apart. If they move towards each other, they will meet in 1 hour. If they
move in the same direction, car A will catch up with car B in 5 hours. Find the speed of car A and
the speed of car B. (Assume that the speeds of the cars are constant.)
Richard has just been given an l0-question multiple-choice quiz in his history class. Each question has five answers, of which only one is correct, Since Richard has not attended a class recently, he doesn't know any of the answers, Assuming that Richard guesses on all 10 questions. Find the indicated probabilities.
A) What is the probability that he will answer all questions correctly?
B) What is the probability that he will answer all questions incorrectly?
C) What is the probability that he will answer at least one of the questions correctly?
Then use the fact that P(r1) = 1 P(r = 0).
D) What is the probability that Richard will answer at least half the questions correctly?
Answer:
a) 0.0000001024 probability that he will answer all questions correctly.
b) 0.1074 = 10.74% probability that he will answer all questions incorrectly
c) 0.8926 = 89.26% probability that he will answer at least one of the questions correctly.
d) 0.0328 = 3.28% probability that Richard will answer at least half the questions correctly
Step-by-step explanation:
For each question, there are only two possible outcomes. Either he answers it correctly, or he does not. The probability of answering a question correctly is independent of any other question. This means that we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
Each question has five answers, of which only one is correct
This means that the probability of correctly answering a question guessing is [tex]p = \frac{1}{5} = 0.2[/tex]
10 questions.
This means that [tex]n = 10[/tex]
A) What is the probability that he will answer all questions correctly?
This is [tex]P(X = 10)[/tex]
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 10) = C_{10,10}.(0.2)^{10}.(0.8)^{0} = 0.0000001024[/tex]
0.0000001024 probability that he will answer all questions correctly.
B) What is the probability that he will answer all questions incorrectly?
None correctly, so [tex]P(X = 0)[/tex]
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{10,0}.(0.2)^{0}.(0.8)^{10} = 0.1074[/tex]
0.1074 = 10.74% probability that he will answer all questions incorrectly
C) What is the probability that he will answer at least one of the questions correctly?
This is
[tex]P(X \geq 1) = 1 - P(X = 0)[/tex]
Since [tex]P(X = 0) = 0.1074[/tex], from item b.
[tex]P(X \geq 1) = 1 - 0.1074 = 0.8926[/tex]
0.8926 = 89.26% probability that he will answer at least one of the questions correctly.
D) What is the probability that Richard will answer at least half the questions correctly?
This is
[tex]P(X \geq 5) = P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10)[/tex]
In which
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 5) = C_{10,5}.(0.2)^{5}.(0.8)^{5} = 0.0264[/tex]
[tex]P(X = 6) = C_{10,6}.(0.2)^{6}.(0.8)^{4} = 0.0055[/tex]
[tex]P(X = 7) = C_{10,7}.(0.2)^{7}.(0.8)^{3} = 0.0008[/tex]
[tex]P(X = 8) = C_{10,8}.(0.2)^{8}.(0.8)^{2} = 0.0001[/tex]
[tex]P(X = 9) = C_{10,9}.(0.2)^{9}.(0.8)^{1} \approx 0[/tex]
[tex]P(X = 10) = C_{10,10}.(0.2)^{10}.(0.8)^{0} \approx 0[/tex]
So
[tex]P(X \geq 5) = P(X = 5) + P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10) = 0.0264 + 0.0055 + 0.0008 + 0.0001 + 0 + 0 = 0.0328[/tex]
0.0328 = 3.28% probability that Richard will answer at least half the questions correctly
Noah has $5.
1.
a.
Elena has 40% as much as Noah. How much does Elena have?
b.
Compare Elena's and Noah's money using fractions. Draw a diagram to
illustrate.
Answer:
a. $4
b. Noah has 5/5. Elena has 4/5.
Step-by-step explanation:
Noah has $5.
a.
Elena has 80% of Noah's money.
80% of $5 = 0.80 * $5 = $4
b.
Noah has $5. We can consider $5 to be the full amount.
A full amount is 100% or 1 or 5/5.
Elena has 80% of Noah's money, so she has 80/100 of Noah's money.
80/100 reduces to 4/5.
Noah has 5/5, and Elena has 4/5.
The money that Elena has is $2.
What is percentage?A percentage is a value that indicates 100th part of any quantity.
A percentage can be converted into a fraction or a decimal by dividing it by 100.
The given problem can be solved as follows,
(a) The amount of money Elena has is 40% of that of Noah.
It can be written as follows,
40% × 5
= 40/100 × 5
= 2
(b) Since the Elena has 40% of the Noah's money,
In the form of fraction it can be written as follows,
40% = 40/100
= 2/5
This can be represented in a diagram as follows,
In the diagram shown the circle has in total 5 sectors of which 2 yellow sectors represent Elena's money.
Hence, the amount of money Elena has is $2 which is shown in the diagram.
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Lucy and Ayu sold a total of 1,080 iPads. Lucy sold 7 times as many as Ayu. How many did each sell
Answer:
let L=lucy and A=ayu
l+a=1080
l=7a 7a+a=1080
8a=1080 8a/8=1080/8
ayu=135
l=7a l=7×135
l=945 so:-135+945=1080
Lucy sold 945 iPads and Ayu sold 135 iPads
What is an equation?"It is a mathematical statement which consists of equal symbol between two algebraic expressions."
For given question,
Let Lucy and Ayu sold 'x' and 'y' iPads respectively.
Lucy and Ayu sold a total of 1,080 iPads.
So, we get an equation,
⇒ x + y = 1080 ...............(i)
Lucy sold 7 times as many as Ayu.
So we get the second equation as,
⇒ x = 7y ................(ii)
Substitute above value of x in equation (i)
⇒ x + y = 1080
⇒ 7y + y = 1080
⇒ 8y = 1080
⇒ y = 135
This means, Ayu sold 135 iPads
Substitute above value of y in equation (ii)
⇒ x = 7(135)
⇒ x = 7 × 135
⇒ x = 945
This means, Lucy sold 945 iPads.
Therefore, Lucy sold 945 iPads and Ayu sold 135 iPads
Learn more about equation here:
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Simplify the expression m 4/5x m1/10
Answer:
√x4
Step-by-step explanation:
(x^2+x−3)⋅(x^2−4)
(y^2+6y+8)−(y^2+y−12)
An electrician charges a service fee of $60 to inspect a home. If he has to
work on something he charges $25 per hour. If he charges $172.50, how
many hours did he work?
Answer:
About 4.5 hours, you can say 5 hours
Step-by-step explanation
You can solve this by constructing a linear equation, which would turn out like this, 25x+60=172.50. How I got this is that it says his charge is 25 per hour, that is basically multiplication by an unknown number, so put that as a variable. Next it says he has a service fee of 60 dollars, this is what's called an initial fee. Now all we need to do is solve for x, which turns into 4.5. I don't know if they ask to round your answer or something, I hope this is right.