Answer: -116 is value of discriminant
2. CTfastrak bus waiting times are uniformly distributed from zero to 20 minutes. Find the probability that a randomly selected passenger will wait the following times for a CTfastrak bus. b. Between 5 and 10 minutes. c. Exactly 7.5922 minutes. d. Exactly 5 minutes. e. Between 15 and 25 minutes.
Answer:
b. 0.25
c. 0.05
d. 0.05
e. 0.25
Step-by-step explanation:
if the waiting time x follows a uniformly distribution from zero to 20, the probability that a passenger waits exactly x minutes P(x) can be calculated as:
[tex]P(x)=\frac{1}{b-a}=\frac{1}{20-0} =0.05[/tex]
Where a and b are the limits of the distribution and x is a value between a and b. Additionally the probability that a passenger waits x minutes or less P(X<x) is equal to:
[tex]P(X<x)=\frac{x-a}{b-a}=\frac{x-0}{20-0}=\frac{x}{20}[/tex]
Then, the probability that a randomly selected passenger will wait:
b. Between 5 and 10 minutes.
[tex]P(5<x<10) = P(x<10) - P(x<5)\\P(5<x<10) = \frac{10}{20} -\frac{5}{20}=0.25[/tex]
c. Exactly 7.5922 minutes
[tex]P(7.5922)=0.05[/tex]
d. Exactly 5 minutes
[tex]P(5)=0.05[/tex]
e. Between 15 and 25 minutes, taking into account that 25 is bigger than 20, the probability that a passenger will wait between 15 and 25 minutes is equal to the probability that a passenger will wait between 15 and 20 minutes. So:
[tex]P(15<x<25)=P(15<x<20) \\P(15<x<20)=P(x<20) - P(x<15)\\P(15<x<20) = \frac{20}{20} -\frac{15}{20}=0.25[/tex]
In a randomly selected sample of 500 Phoenix residents, 445 supported mandatory sick leave for food handlers. Legislators want to be very confident that voters will support this issue before drafting a bill. What is the 99% confidence interval for the percentage of Phoenix residents who support mandatory sick leave for food handlers?
Answer:
The 99% confidence interval for the percentage of Phoenix residents who support mandatory sick leave for food handlers is between 85.40% and 92.60%.
Step-by-step explanation:
Confidence interval for the proportion:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
For this problem, we have that:
[tex]n = 500, \pi = \frac{445}{500} = 0.89[/tex]
99% confidence level
So [tex]\alpha = 0.01[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.01}{2} = 0.995[/tex], so [tex]Z = 2.575[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.89 - 2.575\sqrt{\frac{0.89*0.11}{500}} = 0.8540[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.89 + 2.575\sqrt{\frac{0.89*0.11}{500}} = 0.9260[/tex]
For the percentage:
Multiply the proportion by 100.
0.8540*100 = 85.40%
0.9260*100 = 92.60%
The 99% confidence interval for the percentage of Phoenix residents who support mandatory sick leave for food handlers is between 85.40% and 92.60%.
An article suggests the uniform distribution on the interval (6.5, 19) as a model for depth (cm) of the bioturbation layer in sediment in a certain region.(a) What are the mean and variance of depth
Answer:
The mean of depth is 12.75cm.
The variance of depth is of 13.02 cm².
Step-by-step explanation:
An uniform probability is a case of probability in which each outcome is equally as likely.
For this situation, we have a lower limit of the distribution that we call a and an upper limit that we call b.
The mean of the uniform distribution is:
[tex]M = \frac{a+b}{2}[/tex]
The variance of the uniform distribution is given by:
[tex]V = \frac{(b-a)^{2}}{12}[/tex]
Uniform distribution on the interval (6.5, 19)
This means that: [tex]a = 6.5, b = 19[/tex]
So
Mean:
[tex]M = \frac{6.5+19}{2} = 12.75[/tex]
The mean of depth is 12.75cm.
Variance:
[tex]V = \frac{(19 - 6.5)^{2}}{12} = 13.02[/tex]
The variance of depth is of 13.02 cm².
Solve for in the diagram below.
Answer:
x = 20
Step-by-step explanation:
The sum of the three angles in the diagram is 180 degrees since they form a straight line
x + 100 + 3x = 180
Combine like terms
100 +4x = 180
Subtract 100 from each side
100+4x-100 =180-100
4x= 80
Divide each side by 4
4x/4 = 80/4
x = 20
What is the probability that a senior Physics major and then a sophomore Physics major are chosen at random? Express your answer as a fraction or a decimal number rounded to four decimal places
Answer:
The probability that a senior Physics major and then a sophomore Physics major are chosen at random is 0.0095.
Step-by-step explanation:
The complete question is:
There are 103 students in a physics class. The instructor must choose two students at random.
Students in a Physics Class
Academic Year Physics majors Non-Physics majors
Freshmen 17 15
Sophomores 20 14
Juniors 11 17
Seniors 5 4
What is the probability that a senior Physics major and then a sophomore Physics major are chosen at random? Express your answer as a fraction or a decimal number rounded to four decimal places.
Solution:
There are a total of N = 103 students present in a Physics class.
Some of the students are Physics Major and some are not.
The instructor has to select two students at random.
The instructor first selects a senior Physics major and then a sophomore Physics major.
Compute the probability of selecting a senior Physics major student as follows:
[tex]P(\text{Senior Physics Major})=\frac{n(\text{Senior Physics Major}) }{N}[/tex]
[tex]=\frac{5}{103}\\\\=0.04854369\\\\\approx 0.0485[/tex]
Now he two students are selected without replacement.
So, after selecting a senior Physics major student there are 102 students remaining in the class.
Compute the probability of selecting a sophomore Physics major student as follows:
[tex]P(\text{Sophomore Physics Major})=\frac{n(\text{Sophomore Physics Major}) }{N}[/tex]
[tex]=\frac{20}{102}\\\\=0.1960784314\\\\\approx 0.1961[/tex]
Compute the probability that a senior Physics major and then a sophomore Physics major are chosen at random as follows:
[tex]P(\text{Senior}\cap \text{Sophomore})=P(\text{Senior})\times P(\text{Sophomore})[/tex]
[tex]=0.0485\times 0.1961\\\\=0.00951085\\\\\approx 0.0095[/tex]
Thus, the probability that a senior Physics major and then a sophomore Physics major are chosen at random is 0.0095.
In the past, 35% of the students at ABC University were in the Business College, 35% of the students were in the Liberal Arts College, and 30% of the students were in the Education College. To see whether or not the proportions have changed, a sample of 300 students from the university was taken. Ninety of the sample students are in the Business College, 120 are in the Liberal Arts College, and 90 are in the Education College. This problem is an example of a a. Marascuilo procedure. b. multinomial population. c. z test for proportions. d. test for independence.
Answer:
The correct answer will be Option B (multinomial population).
Step-by-step explanation:
The population is considered as multinomial whether its information is prescriptive or corresponds to the set of discreet non-overlapping groups. The hypothesis again for fitness test besides multinomial distribution is that even though the approximately normal f I seem to be equivalent to the required number e I across each segment.Here, because we have been testing whether the sampling data matches the hypothesized proportions as mentioned, this is indeed a multinomial population issue (because there have been more least two generations).Other given options are not connected to the given situation. So that Option B seems to be the perfect solution.
Erin had 55 stuffed bears. She took out her favorite 7 bears and then equally divided the other bears among her 3 sisters. Erin's youngest sister, Su, already had 15 stuffed bears. How many stuffed bears does Su have now?
Answer:
27 stuffed bears
Step-by-step explanation:
Erin: 55 Su: 15
Erin: 55-7=48 ( 7 will be kept for herself)
Erin and her sisters: 48/4= 12
Each sister besides Erin and Su have 12
Su: 15+12=27
Thus, Su will have 27 stuffed bears
Answer:
31 Stuffed Bears
Step-by-step explanation:
55 - 7 = 48
48 / 3 = 16
16 + 15 = 31
Sue has 31 stuffed bears
Please answer this correctly
Answer:
There are 5 number of temperature readings.
Step-by-step explanation:
9, 7, 9, 10, 9
5 readings recorded in the range of 6-10°C.
find the vector reciprocal to set. a= i+2j+2k, b= 2i+3j+k, c= i-j-2k
Answer:
I just do a' as a sample. You calculate b' and c'
Step-by-step explanation:
[tex]a'=\frac{b\times c}{a\bullet (b\times c)}, b' = \frac{c\times a}{a\bullet (b\times c)}, c' = \frac{a\times b}{a\bullet (b\times c)}[/tex]
Now, calculate b x c
[tex]\left[\begin{array}{ccc}i&j&k\\2&3&1\\1&-1&-2\end{array}\right] =<-5, 5,-5>[/tex]
[tex]a'=\frac{<-5,5,-5>}{<1, 2, 2>\bullet <-5, 5,-5>}=\frac{<-5, 5, -5>}{-5} =<1,-1,1>[/tex]
How many 3-letter codes can be formed if the second letter must be a vowel (a, e, i, o, u)?
Answer:
3,380 combinations
Step-by-step explanation:
26*5*26= 3,380
Answer:
3380
Step-by-step explanation:
Since there are 26 letters, it would be
26*5*26
This is 3380
which of the following describes the zeroes of the graph of f(x)= -x^5+9x^4-18x^3
Answer:
[tex]-x^5+9x^4-18x^3=0\\-x^3(x^2-9x+18)=0\\-x^3(x-3)(x-6)=0\\\\\\\\x=0\\x=3\\x=6[/tex]
If \\(z_1=3+2i\\) and \\(z_2=4+3i\\) and are complex numbers, find \\(z_1z_2\\)
[tex]z_1z_2=(3+2i)(4+3i)=3\cdot4+2i\cdot4+3\cdot3i+2i\cdot3i[/tex]
[tex]z_1z_2=12+8i+9i+6i^2[/tex]
[tex]i^2=-1[/tex], so
[tex]z_1z_2=12+8i+9i-6=\boxed{6+17i}[/tex]
Explain what the number 0 on the gauge represents and explain what the numbers above 0 represent
A 40-foot ladder leans against a building. If
the base of the ladder is 6 feet from the
base of the building, what is the angle
formed by the ladder and the building?
Answer:
Step-by-step explanation:
draw it out and use trig function to solve for the angle. Keep in mind, after getting trig, need to do inverse
What is the answer for this one ?
4x+3y=20 2x+y=7
Answer:
x = 1/2 , y = 6
Explanation:
Step 1 - Align the equations and multiply the second row by 2
4x + 3y = 20
2x + y = 7
4x + 3y = 20
4x + 2y = 14
Step 2 - Subtract them both
4x + 3y = 20
4x + 2y = 14
y = 6
So, y = 6
Step 3 - Substitute y into the first equation
4x + 3y = 20
4x + 3(6) = 20
4x + 18 = 20
Step 4 - Subtract 18 from both sides
4x + 18 = 20
4x + 18 - 18 = 20 - 18
4x = 2
Step 5 - Divide both sides by 4
4x = 2
4x / 4 = 2 / 4
x = 2/4
So, x = 1/2
What is the answer to this question?
Answer:it is b
Step-by-step explanation:
Please answer this correctly
Answer:
17.85 feet.
Step-by-step explanation:
Area = 1/4 * 3.14 * r^2 where r is the radius
So r^2 = 19.625 / (1/4 * 3.14)
r^2 = 25
r = 5 feet.
The perimeter = 2r + 1/4 * 2* 3.14*r
= 2*5 + 7.85
= 17.85 feet.
A garden bed contains 8 tomato plants, 4 squash plants and 8 bell pepper plants. What percentage of the plants are tomato plants
Answer:
33.33%
Step-by-step explanation:
Add them together 8 plus 8 plus 8 which is 24 there are 8 tp so its 8/24 which is equal to 1/3 so the percent is
14 fewer than 12 times the
number of people in my
family is 46.
Answer:
538
Step-by-step explanation:
12 times 46 is 552 then 552 minus 14 is 538
:D
determine whether these two functions are inverses.
Answer:
Yes,these two functions are the inverse of each other.
Step-by-step explanation:
They way of finding if two functions ([tex]f(x)\,\,and\,\,g(x)[/tex] ) are the inverse of each other is by studying if their composition renders in fact the identity. That is, we see if:
[tex]f(x) \,o \,g(x)=f(g(x))=x[/tex]
in our case:
[tex]f(g(x))=\frac{1}{g(x)+4} -9\\f(g(x))=\frac{1}{(\frac{1}{x+9} -4)+4}-9\\f(g(x))=\frac{1}{\frac{1}{x+9} }-9\\f(g(x))={x+9} -9\\f(g(x))=x[/tex]
The composition does render the identity, therefore, these two functions are indeed the inverse of each other
4. The 92 million Americans of age 50 and over control 50% of all discretionary income. AARP estimates that the average annual expenditure on restaurants and carryout food was $1,873 for individuals in the age group. Suppose this estimate is based on a sample of 80 persons and that the sample standard deviation is $550. a. At 95% confidence, what is the margin of error
Answer:
$120.52
Margin of error M.E = $120.52
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
x+/-M.E
Where M.E = margin of error
M.E = zr/√n
Given that;
Mean x = $1,873
Standard deviation r = $550
Number of samples n = 80
Confidence interval = 95%
z(at 95% confidence) = 1.96
Substituting the values we have;
M.E = (1.96 × $550/√80) = 120.5240639872
M.E = $120.52
Margin of error M.E = $120.52
What statement best explains The relationshipBetween numbersDivisible by 5 and 10
Answer:
a number that is divisible by 10 is also divisible by 5 because 5 is a factor of 10.
Step-by-step explanation:
Given : Statement 'The relationship between numbers divisible by 5 and 10'.
To find : What statement BEST explains the statement?
Solution :
First we study the divisibility rules,
Rule for the number divisible by 5 is that number must end in 5 or 0.
Rule for the number divisible by 10 is that number need to be even and divisible by 5, as the prime factors of 10 are 5 and 2 and the number to be divisible by 10, the last digit must be a 0.
According to the divisibility rules Option D is correct.
Therefore, The correct statement explains the relationship between numbers divisible by 5 and 10 is a number that is divisible by 10 is also divisible by 5 because 5 is a factor of 10.
The math SAT is scaled so that the mean score is 500 and the standard deviation is 100. Assuming scores are normally distributed, find the probability that a randomly selected student scores
Answer:
a. P(X>695)=0.026
b. P(X<485)=0.44
Step-by-step explanation:
The question is incomplete:
a. higher than 695 on the test.
b. at most 485 on the test.
We have a normal distribution with mean 500 and standard deviation of 100 for the test scores. We will use the z-scores to calculate the probabilties with the standard normal distribution table.
a. We want to calculate the probability that a randomly selected student scores higher than 695.
We calculate the z-score and then we calculate the probability:
[tex]z=\dfrac{X-\mu}{\sigma}=\dfrac{695-500}{100}=\dfrac{195}{100}=1.95\\\\\\P(X>695)=P(z>1.95)=0.026[/tex]
a. We want to calculate the probability that a randomly selected student scores at most 485.
We calculate the z-score and then we calculate the probability:
[tex]z=\dfrac{X-\mu}{\sigma}=\dfrac{485-500}{100}=\dfrac{-15}{100}=-0.15\\\\\\P(X<485)=P(z<-0.15)=0.44[/tex]
what’s the sum of x+x^2+2 and x^2-2-x ?
Answer: The correct answer is: " 2x² " .
________________________________
Step-by-step explanation:
________________________________
We are asked: "What is the sum of: "x + x² + 2" and "x² − 2 − x" ?
Since we are to find the "sum" ;
→ We are to "add" these 2 (two) expressions together:
→ (x + x² + 2) + (x² − 2 − x) ;
Note: Let us rewrite the above, by adding the number "1" as a coefficient to: the values "x" ; and "x² " ; since there is an "implied coefficient of "1" ;
→ {since: "any value" ; multiplied by "1"; results in that exact same value.}.
→ (1x + 1x² + 2) + (1x² − 2 − 1x) ;
Rewrite as:
→ 1x + 1x² + 2) + (1x² − 2 − 1x) ;
Now, let us add the "coefficient" , "1" ; just before the expression:
"(1x² − 2 − 1x)" ;
{since "any value", multiplied by "1" , equals that same value.}.
And rewrite the expression; as follows:
→ (1x + 1x² + 2) + 1(1x² − 2 − 1x) ;
Now, let us consider the following part of the expression:
→ " +1(1x² − 2 − 1x) " ;
________________________________
Note the distributive property of multiplication:
→ " a(b+c) = ab + ac " ;
and likewise:
→ " a(b+c+d) = ab + ac + ad " .
________________________________
So; we have:
→ " +1(1x² − 2 − 1x) " ;
= (+1 * 1x²) + (+1 *-2) + (+1*-1x) ;
= + 1x² + (-2) + (-1x) ;
= +1x² − 2 − 1x ;
↔ ( + 1x² − 1x − 2)
Now, bring down the "left-hand side of the expression:
1x + 1x² + 2 ;
and add the rest of the expression:
→ 1x + 1x² + 2 + 1x² − 1x − 2 ;
________________________________
Now, simplify by combining the "like terms" ; as follows:
+1x² + 1x² = 2x² ;
+1x − 1x = 0 ;
+ 2 − 2 = 0 ;
________________________________
The answer is: " 2x² " .
________________________________
Hope this is helpful to you!
Best wishes!
________________________________
Answer:
The correct answer is: " 2x² " .
________________________________
Step-by-step explanation:
________________________________
We are asked: "What is the sum of: "x + x² + 2" and "x² − 2 − x" ?
Since we are to find the "sum" ;
→ We are to "add" these 2 (two) expressions together:
→ (x + x² + 2) + (x² − 2 − x) ;
Note: Let us rewrite the above, by adding the number "1" as a coefficient to: the values "x" ; and "x² " ; since there is an "implied coefficient of "1" ;
→ {since: "any value" ; multiplied by "1"; results in that exact same value.}.
→ (1x + 1x² + 2) + (1x² − 2 − 1x) ;
Rewrite as:
→ 1x + 1x² + 2) + (1x² − 2 − 1x) ;
Now, let us add the "coefficient" , "1" ; just before the expression:
"(1x² − 2 − 1x)" ;
{since "any value", multiplied by "1" , equals that same value.}.
And rewrite the expression; as follows:
→ (1x + 1x² + 2) + 1(1x² − 2 − 1x) ;
Now, let us consider the following part of the expression:
→ " +1(1x² − 2 − 1x) " ;
________________________________
Note the distributive property of multiplication:
→ " a(b+c) = ab + ac " ;
and likewise:
→ " a(b+c+d) = ab + ac + ad " .
________________________________
So; we have:
→ " +1(1x² − 2 − 1x) " ;
= (+1 * 1x²) + (+1 *-2) + (+1*-1x) ;
= + 1x² + (-2) + (-1x) ;
= +1x² − 2 − 1x ;
↔ ( + 1x² − 1x − 2)
Now, bring down the "left-hand side of the expression:
1x + 1x² + 2 ;
and add the rest of the expression:
→ 1x + 1x² + 2 + 1x² − 1x − 2 ;
________________________________
Now, simplify by combining the "like terms" ; as follows:
+1x² + 1x² = 2x² ;
+1x − 1x = 0 ;
+ 2 − 2 = 0 ;
________________________________
The answer is: " 2x² " .
Step-by-step explanation:
A potter made 4080 diyas in the month of September. If he made the same number of diyas each day, how many diyas did he make in a week?
Problem PageQuestion A Web music store offers two versions of a popular song. The size of the standard version is 2.6 megabytes (MB). The size of the high-quality version is 4.2 MB. Yesterday, the high-quality version was downloaded four times as often as the standard version. The total size downloaded for the two versions was 4074 MB. How many downloads of the standard version were there?
Answer:
There were 210 downloads of the standard version.
Step-by-step explanation:
This question can be solved using a system of equations.
I am going to say that:
x is the number of downloads of the standard version.
y is the number of downloads of the high-quality version.
The size of the standard version is 2.6 megabytes (MB). The size of the high-quality version is 4.2 MB. The total size downloaded for the two versions was 4074 MB.
This means that:
[tex]2.6x + 4.2y = 4074[/tex]
Yesterday, the high-quality version was downloaded four times as often as the standard version.
This means that [tex]y = 4x[/tex]
How many downloads of the standard version were there?
This is x.
[tex]2.6x + 4.2y = 4074[/tex]
Since [tex]y = 4x[/tex]
[tex]2.6x + 4.2*4x = 4074[/tex]
[tex]19.4x = 4074[/tex]
[tex]x = \frac{4074}{19.4}[/tex]
[tex]x = 210[/tex]
There were 210 downloads of the standard version.
Please answer this correctly
Answer:
A=450
Step-by-step explanation:
A=a+b
2h=12+33
2·20=450
Answer:
Area=450
Step-by-step explanation:
[tex]a+b/2h[/tex]
What’s the correct answer for this question?
Answer:
A.
Step-by-step explanation:
In the attached file
Forty adult men in the United States are randomly selected and measured for their body mass index (BMI). Based on that sample, it is estimated that the average (mean) BMI for men is 25.5, with a margin of error of 3.3. Use the given statistic and margin of error to identify the range of values (confidence interval) likely to contain the true value of the population parameter
Answer:
[tex] 25.5 -3.3= 22.2[/tex]
[tex] 25.5 +3.3= 28.8[/tex]
And the confidence interval would be given by: [tex] 22.2\leq \mu \leq 28.8[/tex]
Step-by-step explanation:
[tex]\bar X=25.5[/tex] represent the sample mean for the sample
ME= 3.3 represent the margin of error
Confidence interval
The confidence interval for the mean is given by the following formula:
[tex]\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}[/tex] (1)
The margin of error is given by;
[tex] ME =t_{\alpha/2}\frac{s}{\sqrt{n}}= 3.3[/tex]
And the confidence interval would be given by:
[tex] 25.5 -3.3= 22.2[/tex]
[tex] 25.5 +3.3= 28.8[/tex]
And the confidence interval would be given by: [tex] 22.2\leq \mu \leq 28.8[/tex]
John conducted a taste test on a new brand of French fries. He gave each participant 5 of the new brand of fries and 5 of the old brand of fries and asked them to rate which brand they preferred. The participants rated both brands of fries as equally preferable. Based on this, he recommended to the manufacturer to move ahead with producing this new brand. However, the brand did not sell well. People reported feeling nauseous after they had consumed a whole portion.
Which validity is weak in this example?
a. internal validity
b. external validity
c. statistical validity
d. construct validity
Answer:
b. external validity
Step-by-step explanation:
External Validity is the applicability of the results of an experiment to the real world. Most times, there are threats to the validity of an experiment which could result in little or no effect on the general population. For example, if the method of selection reflects a measure of bias, then this could affect the result. Also if the participants are taking different aspects of the same test, it could also affect its validity as they may not be able to make a correct conclusion. If the sample size is not reflective of the entire population, it could also pose a threat to the validity of the experiment.
John's experiment is weak in its external validity because it cannot be generalized to the entire population of customers. He has to identify the threats to the validity of his experiment and correct them. For example, the sample selection may be biased.
