Two trains leave the train station at 10:00 a.m. and travel in opposite directions. Their rates are 65 mph and 85 mph. How many hours will it take for them to be 450 miles apart?
Answer:
Step-by-step explanation:
The distance between trains increases by 65+85 = 150 mph.
450 miles × (1 hour)/(150 miles) = 3 hours
An art history professor assigns letter grades on a test according to the following scheme. A: Top 13% of scores B: Scores below the top 13% and above the bottom 56% C: Scores below the top 44% and above the bottom 21% D: Scores below the top 79% and above the bottom 9% F: Bottom 9% of scores Scores on the test are normally distributed with a mean of 79.7 and a standard deviation of 8.4. Find the numerical limits for a B grade. Round your answers to the nearest whole number, if necessary.
Answer:
The numerical limits for a B grade are 81 and 89, that is, a score between 81 and 89 gets a B grade.
Step-by-step explanation:
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.
Scores on the test are normally distributed with a mean of 79.7 and a standard deviation of 8.4.
This means that [tex]\mu = 79.7, \sigma = 8.4[/tex]
B: Scores below the top 13% and above the bottom 56%
So between the 56th percentile and the 100 - 13 = 87th percentile.
56th percentile:
X when Z has a p-value of 0.56, so X when Z = 0.15. Then
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]0.15 = \frac{X - 79.7}{8.4}[/tex]
[tex]X - 79.7 = 0.15*8.4[/tex]
[tex]X = 81[/tex]
87th percentile:
X when Z has a p-value of 0.87, so X when Z = 1.13.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]1.13 = \frac{X - 79.7}{8.4}[/tex]
[tex]X - 79.7 = 1.13*8.4[/tex]
[tex]X = 89[/tex]
The numerical limits for a B grade are 81 and 89, that is, a score between 81 and 89 gets a B grade.
A survey was held to find the time taken by students to reach school from
their homes. Each student was asked to choose from 5, 10, 15, 20, or 25
minutes.
Number of
Minutes 5 10 15 20 25
Number of
Students
11
8
2
3
6
What is the mode for the data set?
A. 5 min b. 10 min c. 20 min d. 25 min
Hello,
in France, the mode is the value having the greater repetition
mode= 5 (repetition=11)
hello can anyone help with this?
Answer:
<2 and <13 are alternate exterior angles.
In simple form, alternate exterior angles are the opposite angle on the opposing parallel line. So, to make you understand better, <4 and <15 are alternate exterior angles.
Hope this helps :D
Find the area of
1.Table
Length = 123cm
Width = 82cm
Height = 76cm
2.Living room
Length = 422cm
Width = 278cm
Height = 253cm
3. Door
Length = 87cm
Width = 2.3cm
Height = 208cm
Answer:
1. 766,536cm^3
2. 29,680,948cm^3
3. 41,620.8cm^3
Step-by-step explanation:
1. 123×82 = 10,086 10,086×76 = 766,536
2. 422×278 = 117,316 117,316×253 = 29,680,948
3. 87×2.3 = 200.1 200.1×208 = 41,620.8
Hope this helps! :)
What is the coefficient of x2 in the expansion of (x + 2)??
O A.
2
OB.
3
O C.
4
OD.
6
x+2 in expansion of (x+2) ?
A
We have 9 pens, of which 5 are green ink, 3 are red ink, and 1 is black. If we put the pens in a line, how many arrangements are possible
Answer:
504 arrangements are possible
Step-by-step explanation:
Arrangements of n elements:
The number of arrangements of n elements is given by:
[tex]A_{n} = n![/tex]
Arrangements of n elements, divided into groups:
The number of arrangements of n elements, divided into groups of [tex]n_1, n_2,...,n_n[/tex] elements is given by:
[tex]A_{n}^{n_1,n_2,...,n_n} = \frac{n!}{n_1!n_2!...n_n!}[/tex]
In this case:
9 pens, into groups of 5, 3 and 1. So
[tex]A_{9}^{5,3,1} = \frac{9!}{5!3!1!} = 504[/tex]
504 arrangements are possible
express the ratio as a fraction in it's lowest terms.3kg to 800g
Answer:
15 / 4
Step-by-step explanation:
1 kg = 1000 g
3 kg
= 3 x 1000
= 3000 g
3kg to 800g
= 3kg : 800g
= 3000 : 800
= 30 : 8
= 30 / 8
= 15 / 4
15/4 is the fraction representing the ratio of 3 kilograms to 800 grams.
To express the ratio of 3 kilograms to 800 grams as a fraction in its lowest terms.
we need to convert both the quantities to the same units. Since 1 kg is equal to 1000 g, we can convert 3 kg to grams as follows:
3 kg = 3 * 1000 g = 3000 g
Now, we have the quantities in the same unit, and the ratio becomes:
3000 g to 800 g
To express this ratio as a fraction, we place the quantities over each other:
3000 g
-------
800 g
Now, to simplify the fraction to its lowest terms, we find the greatest common divisor (GCD) of the two numbers (3000 and 800) and divide both the numerator and denominator by this GCD.
The GCD of 3000 and 800 is 200, so dividing both by 200 gives us:
3000 ÷ 200 = 15
800 ÷ 200 = 4
Therefore, the ratio 3 kg to 800 g expressed as a fraction in its lowest terms is 15/4.
In summary, we first converted the units to the same (grams) to make the ratio easier to handle. Then, we represented the ratio as a fraction and simplified it to its lowest terms using the GCD method. The final answer, 15/4, is the fraction representing the ratio of 3 kilograms to 800 grams.
To know more about Fraction here
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Which function has no horizontal asymptote?
Answer:
[tex]{ \tt{f(x) = \frac{x - 1}{3x} }}[/tex]
Answer:
c
Step-by-step explanation:
edge
Determine whether the value is a discrete random variable, continuous random variable, or not a random variable. a. The number of people with blood type A in a random sample of 26 people b. The exact time it takes to evaluate 27+72 c. The gender of college students d. The number of hits to a website in a day e. The number of bald eagles in a country f. The distance a baseball travels in the air after being hit a. Is the number of people with blood type A in a random sample of 26 people a discrete random variable, a continuous random variable, or not a random variable?
Answer:
a) it is a discrete random variable
b) It is a continuous random variable
c) It is not a random variable
d) It is a discrete random variable
e) It is a discrete random variable
f) It is a continuous random variable
Step-by-step explanation:
Explanation,
Continuous Random Variable
A continuous variable is one that can take on an uncountable set of values.
It may take any values within an interval.
It can take infinite values within an interval.
They are obtained by measuring rather than counting.
Discrete Random Variable
These can only take a discrete value and cannot be expressed in the form of decimals.
They are obtained by counting rather than measuring.
a). it is a discrete random variable ⇒ as a number of people is a discrete count, which takes values such as 0 or 1 or 2.
b). The exact time it takes to evaluate 27+72 ⇒ Since, Time is measured and thus it is a continuous random variable.
c). The gender of college students ⇒ Gender is categorical data. It is neither continuous nor discrete.
d). The number of hits to a website in a day ⇒ Since the number of people cannot be expressed as decimals, thus it is a discrete random variable
e). The number of bald eagles in a country ⇒ Since the number of people cannot be expressed as decimals, thus it is a discrete random variable
f). The distance a baseball travels in the air after being hit ⇒ Distance is measured and thus it is a continuous random variable.
In a group of 450 students, 250 like oranges 280 like apples and 40 dislike both
the fruits
Answer:
Could you please question correctly??
Step-by-step explanation:
Total Students:450
Oranges:250
Apples:280
Dislike:40
like:280-250+40
Answer
i dont see the question sorry
Plz get me the correct answer or u will be reported. 15 points for correct answer. Thx.
Answer:
D
Step-by-step explanation:
correct answer, thanks for 15 pts
Answer:
Option D is correct
Step-by-step explanation:
Hope it is helpful....
Complete the following statement.
The mean of Restaurant A's service ratings is _____ the mean of Restaurant's B service ratings.
A. The same as
B. Worse than
C. Better than
A sample of the salaries of assistant professors on the business faculty at a local university revealed a mean income of $100,000 with a standard deviation of $10,000. Assume that salaries follow a bell-shaped distribution. Use the empirical rule:
a. Approximately what percentage of the salaries fall between $90,000 and $110,000?
b. Approximately what percentage of the salaries fall between $80,000 and $120,000?
c. Approximately what percentage of the salaries are greater than $120,000?
Answer:
a) 68%
b) 95%.
c) 2.5%
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
Approximately 68% of the measures are within 1 standard deviation of the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean of 100,000, standard deviation of 10,000.
a. Approximately what percentage of the salaries fall between $90,000 and $110,000?
90,000 = 100,000 - 10,000
110,000 = 100,000 + 10,000
Within 1 standard deviation of the mean, so approximately 68%.
b. Approximately what percentage of the salaries fall between $80,000 and $120,000?
80,000 = 100,000 - 2*10,000
120,000 = 100,000 + 2*10,000
Within 2 standard deviations of the mean, so approximately 95%.
c. Approximately what percentage of the salaries are greater than $120,000?
More than 2 standard deviations above the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean, so approximately 5% are more than 2 standard deviations from the mean.
The normal distribution is symmetric, which means that 2.5% are more then 2 standard deviations below the mean, and 2.5% are more than 2 standard deviations above the mean, which means that 2.5% of the salaries are greater than $120,000.
Integration of [(x+1)/(x-1)]dx
Hello!
∫[(x+1)/(x-1)dx
∫t+2/t dt
∫t/t + 2/t dt
∫1 + 2/t dt
∫1dt + ∫2/t dt
∫t + 2In (|t|)
x - 1 + 2In (|x-1|)
x + 2In (|x-1|) + C, C ∈ R
Good luck! :)
A papaya is accidentally dropped from a bridge, which is 30 m above the water. Ignoring air resistance, the papaya's speed just before it hits the water will be __________ m/s.
Answer:
24 .30ms is the answer I think so if the answer is correct plz mark me as brainliest.
The papaya's speed just before it hits the water will be 24.24 m/s.
What is speed?The rate at which objects moves is called speed. It is given by
[tex]s = \frac{d}{t}[/tex]
An object held above the ground has a potential energy related to the height at which it is held,
PE = mgh
If you drop the object, its potential energy will become the kinetic energy of motion:
KE = ½ mv²
½ mv² = mgh
v = √(2gh)
v = √(2*9.8*30)
v = 24.24 m/s
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There is a bag filled with 3 blue and 5 red marbles.
A marble is taken at random from the bag, the colour is noted and then it is not replaced.
Another marble is taken at random.
What is the probability of getting 2 of the same colour?
JUST NEED THE ANSWER IN A FRACTION PLEASE
[tex]\frac{13}{28}[/tex]
Step-by-step explanation:Given:
Blue marbles: 3
Reb marbles: 5
Total marbles: 8
Two marbles are selected at random, one after the other with replacement.
Getting the same colour of marbles from the selection means the two marbles are both red or both blue.
(a) Probability of getting 2 marbles being red in colour
i. Probability of picking a red at the first selection:
Number of red marbles ÷ Total number of marbles
=> 5 ÷ 8 = [tex]\frac{5}{8}[/tex]
ii. Probability of picking a red at the second selection:
Number of remaining red marbles ÷ Total number of remaining marbles
Since after the first pick, the marble is not replaced, the remaining red marbles is 4 while the total number of remaining marbles is 7
=> 4 ÷ 7 = [tex]\frac{4}{7}[/tex]
iii. The probability of getting both marbles being red is the product of i and ii above. i.e
[tex]\frac{5}{8}[/tex] x [tex]\frac{4}{7}[/tex] = [tex]\frac{5}{14}[/tex]
(b) Probability of getting 2 marbles being blue in colour
i. Probability of picking a blue at the first selection:
Number of blue marbles ÷ Total number of marbles
=> 3 ÷ 8 = [tex]\frac{3}{8}[/tex]
ii. Probability of picking a blue at the second selection:
Number of remaining blue marbles ÷ Total number of remaining marbles
Since after the first pick, the marble is not replaced, the remaining blue marbles is 2 while the total number of remaining marbles is 7
=> 2 ÷ 7 = [tex]\frac{2}{7}[/tex]
iii. The probability of getting both marbles being blue is the product of i and ii above. i.e
[tex]\frac{3}{8}[/tex] x [tex]\frac{2}{7}[/tex] = [tex]\frac{3}{28}[/tex]
(c) Probability of getting 2 marbles of the same colour.
The probability of getting 2 marbles of same colour is the sum of the probability of getting both marbles of red colour and the probability of getting both marbles as blue colour. i.e The sum of a(iii) and b(iii)
[tex]\frac{5}{14}[/tex] + [tex]\frac{3}{28}[/tex] = [tex]\frac{13}{28}[/tex]
The probability of getting 2 of the same colour is [tex]\frac{13}{28}[/tex]
jimmy had twice as many oranges as grapefruit, 5 more grapefruits than pineapples, how many of each fruit did jimmy have?
Answer:
Step-by-step explanation:
I think he has 7 oranges and 5 grapefruit and ten pineapples
2 triangles are shown. The first triangle has side lengths 35, 20, and 20. The second triangle has side lengths x, 44, 44.
What value of x will make the triangles similar by the SSS similarity theorem?
15.9
59
77
96.8
Answer:
[tex]x = 77[/tex]
Step-by-step explanation:
Given
[tex]First \to Second[/tex]
[tex]35 \to x[/tex]
[tex]20 \to 44[/tex]
[tex]20 \to 44[/tex]
Required
Find x by SSS
Represent the triangle sides as a ratio
[tex]35 : x = 20 : 44[/tex]
Express as fraction
[tex]\frac{x}{35} = \frac{44}{20}[/tex]
Multiply by 35
[tex]x = \frac{44}{20} * 35[/tex]
[tex]x = \frac{44 * 35}{20}[/tex]
[tex]x = \frac{1540}{20}[/tex]
[tex]x = 77[/tex]
Answer:
ccccccccccccccccccccccccccc
Step-by-step explanation:
whats the x and y value? I thought it would be choice d but I'm not sure
please help asap . my question is timed
Answer:
cos(60°) = [tex]\frac{adjacent}{hypotenuse}=\frac{y}{10\sqrt{3} }[/tex]
[tex]cos(60)=\frac{y}{10\sqrt{3} } \\y=cos(60) * 10\sqrt{3} \\y=\frac{1}{2} * 10\sqrt{3}\\y=\frac{10\sqrt{3}}{2} =5\frac{\sqrt{3} }{2} =8.66[/tex]
sin(60°) = [tex]\frac{opposite}{hypotenuse} =\frac{x}{10\sqrt{3} }[/tex]
[tex]sin(60)=\frac{x}{10\sqrt{3} } \\x=sin(60)*10\sqrt{3} \\x=\frac{\sqrt{3} }{2} *10\sqrt{3} \\x=\frac{10(\sqrt{3} ) (\sqrt{3} )}{2} \\x=\frac{10*3}{2} =\frac{30}{2} =15[/tex]
How many cubes with side lengths of 1/2 cm does it take to fill the prism?
Answer:
24
Step-by-step explanation:
You first find out how many cubes can fit into each measurement, then multiply them. (2*4*3=24)
Answer:
It will take 24 cubes to fill the rectangular prism.
Step-by-step explanation:
Find the volume of a cube with side lengths of 1/2 cm:
1/2^3 = 1/8
1/8 cm^3
Find the volume of the whole rectangular prism (lwh):
1 x 3/2 x 2
= 3/2 x 2
= 3
3 cm^3
Divide the volume of the prism by the bolume of one cube:
3 ÷ 1/8 = 24
Therefore it will take 24 cubes to fill the prism. Hope this helps!
The probability that an individual has 20-20 vision is 0.18. In a class of 12 students, what is the probability of finding five people with 20-20 vision?
0.417 or 0.185 or 0.18 or 0.037
Answer:
0.417
Step-by-step explanation:
Just divide 12/5 and the answer is 0.416666666...
Round up and you get 0.417.
Hope this helped!
Can someone help me please?
the abswer of this question is c
By converting to an exponential expression, solve log2 (x + 5) = 4
Step-by-step explanation:
just insert a base of two at on both sides and solve.
The solution of the logarithmic equation ㏒ (x + 5) / ㏒ 2 = 4 will be 11.
What is the solution to the equation?The allocation of weights to the important variables that produce the calculation's optimum is referred to as a direct consequence.
The logarithmic equation is given below.
㏒₂(x + 5) = 4
Simplify the equation, then we have
㏒ (x + 5) / ㏒ 2 = 4
㏒ (x + 5) = 4 × ㏒ 2
㏒ (x + 5) = ㏒ 2⁴
Take antilog on both sides, then we have
(x + 5) = 2⁴
(x + 5) = 16
x = 11
The solution of the logarithmic equation ㏒ (x + 5) / ㏒ 2 = 4 will be 11.
More about the solution of the equation link is given below.
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Will give brainliest answer, there has to be two answers to give one of you the brainliest
Answer:
C
Step-by-step explanation:
[tex] ({8}^{ { - 9})^{ \frac{ - x}{9} } } [/tex]
when putting a power to another power, then these two powers are multiplied.
so, -9 × (-x/9) = (-9 × -x) / 9 = 9x/9 = x
so, this reduces to the original
[tex] {8}^{x} [/tex]
and therefore C is the right answer.
On a 9 question multiple-choice test, where each question has 5 answers, what would be the probability of getting at least one question wrong?
Answer:
P(at least one wrong) = 1- P(all correct) =1-.25^6=1-1/4096=4095/4096. This assumes that the answers are picked at random. This kind of question is always the complement of an extreme binomial outcome.
Lena and Ras drive to work. Lena drives 24 miles in 1.5 hours. Ras drives 36 km in 1 hour 15 min. Work out the difference between their average speeds in km/h. 1 mile = 1.6 km
Answer:
Difference = 3.2 km/h
Step-by-step explanation:
Given that,
Lena drives 24 miles in 1.5 hours. Ras drives 36 km in 1 hour 15 min.
For average speed of Lena,
d = 24 miles = 38.4 km
t = 1.5 h
[tex]v=\dfrac{38.4}{1.5}= 25.6\ km/h[/tex]
For average speed of Ras,
d = 36 km
t = 1h 15 min = 1.25 h
[tex]v=\dfrac{36}{1.25}=28.8\ km/h[/tex]
Difference = 28.8-25.6
= 3.2 km/h
So, the difference between their average speed is 3.2 km/hr.
Answer:
3.2 km/h
Step-by-step explanation:
A survey found that the median number of calories consumed per day in a certain country was 3,304 and the mean was 3,204.9 calories. If a histogram were constructed for the data, would you expect it to be skewed to the right, to the left, or approximately symmetric
Answer:
Skewed to the left
Step-by-step explanation:
Given
[tex]Median = 3304[/tex]
[tex]Mean = 3204.9[/tex]
Required
The type of distribution
From the given data, we have:
[tex]Median \ne Mean[/tex] --- Mean and Median are not equal
and
[tex]Median > Mean[/tex] --- Median is greater than mean
When the median is greater than the mean; the histogram is expected to be left skewed
12. A professor creates a boxplot of test scores for 26 students in a statistics course. What percentage of students scored above 81
Answer:
25%
Step-by-step explanation:
Based on the boxplot given ;
The boxplot can be summarized as follows :
Lower quartile, Q1 = 50 (starting point of the box)
Median (Q2), 50th percentile = 70 (vertical line in between the box)
The upper quartile marks the 75th percentile, Q3 = 81 (end point of the box)
The total distribution is 100% and hence, the percentage above the score 81 will be :
100% - 75% = 25%
is this right please answer ill mark!!
Answer:
yeah u r correct..Step-by-step explanation:
hope it helps.stay safe healthy and happy......Answer:
yes
Step-by-step explanation:
cos=adjacent over hypotenouse
