Answer:
4r + 4(r + 3) = 68
r = 7 miles per hour
r + 3 = 10 miles per hour
Step-by-step explanation:
distance = rate * time
a)
4r + 4(r + 3) = 68
Distribute
4r + 4r + 12 = 68
8r + 12 = 68
8r = 56
r = 7 miles per hour
r + 3 = 10 miles per hour
(a) The heights of male students in a college are thought to be normally distributed with mean 170 cm and standard deviation 7.
The heights of 5 male students from this college are measured and the sample mean was 174 cm.
Determine, at 5% level of significance, whether there is evidence that the mean height of the male students of this college is higher than 170 cm.
[6]
(b) (i) The result of a fitness trial is a random variable X which is normally distributed with mean μ and standard deviation 2.4 . A researcher uses the results from a random sample of 90 trials to calculate a
98% confidence interval for μ . What is the width of this interval?
[4]
(ii) Packets of fish food have weights that are distributed with standard deviation 2.3 g. A random sample of 200 packets is taken. The mean weight of this sample is found to be 99.2 g. Calculate a 99% confidence interval for the population mean weight.
[4]
(c) (i) Explain the difference between a point estimate and an interval
Estimate. [2]
(ii) The daily takings, $ x, for a shop were noted on 30 randomly chosen days. The takings are summarized by Σ x=31 500 and
Σ x2=33 141 816 .
Calculate unbiased estimates of the population mean and variance of the shop’s daily taking. [4
Answer:
the answer is 50 but I don't know if
The principle of redundancy is used when system reliability is improved through redundant or backup components. Assume that a student's alarm clock has a 15.3% daily failure rate. Complete parts (a) through (d) below. a. What is the probability that the student's alarm clock will not work on the morning of an important final exam?
Answer:
[tex]Pr = 0.153[/tex]
Step-by-step explanation:
Given
[tex]p = 15.3\%[/tex]
Required
Probability of alarm not working
[tex]p = 15.3\%[/tex] implies that the alarm has a probability of not working on a given day.
So, the probability that the alarm will not work on an exam date is:
[tex]Pr = 15.3\%[/tex]
Express as decimal
[tex]Pr = 0.153[/tex]
Pls help this is rlly important!! You’ll get branliest bc this is hard and I’m stuck.
the median of restaurant b's cleanliness ratings is 2.
the median of restaurant b's food quality ratings is 4.
the median of restaurant b's service ratings is 3.
:))
Simplify the given expression below:
(4 + 21) – (1 – 71)
Hey there!
(4 + 21) - (1 - 71)
4 + 21 = 25
= 25 - (1 - 71)
1 - 71 = -70
= 25 - (-70)
= 25 + 70
= 95
Answer: 95
Good luck on your assignment and enjoy your day!
~Amphitrite1040:)
In a given region, the number of tornadoes in a one-week period is modeled by a Poisson distribution with mean 2. The numbers of tornadoes in different weeks are mutually independent. Calculate the probability that fewer than four tornadoes occur in a three-week period.
Answer:
0.1512 = 15.12% probability that fewer than four tornadoes occur in a three-week period.
Step-by-step explanation:
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:
[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]
In which
x is the number of sucesses
e = 2.71828 is the Euler number
[tex]\mu[/tex] is the mean in the given interval.
In a given region, the number of tornadoes in a one-week period is modeled by a Poisson distribution with mean 2
Three weeks, so [tex]\mu = 2*3 = 6[/tex]
Calculate the probability that fewer than four tornadoes occur in a three-week period.
This is:
[tex]P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)[/tex]
In which
[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]
[tex]P(X = 0) = \frac{e^{-6}*6^{0}}{(0)!} = 0.0025[/tex]
[tex]P(X = 1) = \frac{e^{-6}*6^{1}}{(1)!} = 0.0149[/tex]
[tex]P(X = 2) = \frac{e^{-6}*6^{2}}{(2)!} = 0.0446[/tex]
[tex]P(X = 3) = \frac{e^{-6}*6^{3}}{(3)!} = 0.0892[/tex]
Then
[tex]P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) = 0.0025 + 0.0149 + 0.0446 + 0.0892 = 0.1512[/tex]
0.1512 = 15.12% probability that fewer than four tornadoes occur in a three-week period.
what is the complete factorization of 8x^2-8x+2
Answer:
2x(4x-4+1)
Step-by-step explanation:
i hope it will help you
Answer:
x=1/2
Step-by-step explanation:
press the calculator
8x²-8x+2=0
x=1/2
min,x=1/2
min,y=0
Verify that the equation is an identity.
Step-by-step explanation:
We need to prove that ,
cot x / csc x - csc x / cot x = - tan x sec x .
LHS :-
> cot x / csc x - csc x / cot x
> cos x / sin x ÷ csc x - sin x × csc x / cos x
> cosx - 1/ cos x
> cos² x - 1 / cos x
> - sin²x / cosx
> -sin x / cos x × sin x
> -tan x sin x
= RHS
Hence Proved !
For each of the following variables, identify the type of variable (categorical vs. numeric). (1) Temperature (in Fahrenheit) of an office building (11) Traffic congestion (e.g. light, medium, heavy)
1) (1) Numeric, and (II) Categorical
2) (1) Numeric, and (II) Numeric
3) (1) Categorical, and (II) Numeric
4) There is no correct match.
5) (1) Categorical, and (11) Categorical
Answer:
(a) Temperature: Numerical
(b) Traffic congestion: Categorical
Step-by-step explanation:
Required
Determine the variable type
(a) Temperature
Temperatures are measured in numeric values e.g. 22 degree Fahrenheit, etc.
Hence, the variable is numerical
(b) Traffic congestion
From the question, we understand that the traffic congestion are divided into three categories i.e. light, medium....
Hence, the variable is categorical
What is the correct equation for the graph?
tan graph and its tax because tax=0
Which point is part of the solution of the inequality y ≤ |x + 4| − 3?
Answer:
Step-by-step explanation:
The cost of 5 gallons of ice cream has a variance of 64 with a mean of 34 dollars during the summer. What is the probability that the sample mean would differ from the true mean by less than 1.1 dollars if a sample of 38 5-gallon pails is randomly selected
Answer:
0.5587 = 55.87% probability that the sample mean would differ from the true mean by less than 1.1 dollars.
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 establishes 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 cost of 5 gallons of ice cream has a variance of 64 with a mean of 34 dollars during the summer.
This means that [tex]\sigma = \sqrt{64} = 8, \mu = 34[/tex]
Sample of 38
This means that [tex]n = 38, s = \frac{8}{\sqrt{38}}[/tex]
What is the probability that the sample mean would differ from the true mean by less than 1.1 dollars ?
P-value of Z when X = 34 + 1.1 = 35.1 subtracted by the p-value of Z when X = 34 - 1.1 = 32.9. So
X = 35.1
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{35.1 - 34}{\frac{8}{\sqrt{38}}}[/tex]
[tex]Z = 0.77[/tex]
[tex]Z = 0.77[/tex] has a p-value of 0.77935
X = 32.9
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{32.9 - 34}{\frac{8}{\sqrt{38}}}[/tex]
[tex]Z = -0.77[/tex]
[tex]Z = -0.77[/tex] has a p-value of 0.22065
0.77935 - 0.22065 = 0.5587
0.5587 = 55.87% probability that the sample mean would differ from the true mean by less than 1.1 dollars.
help? haha
solve the equation below:)
3x - 5 = 10 + 2x
Step-by-step explanation:
3x-2x=5+10 [taking variables on one side and constant on other]
x=15
soln:
3x-5= 2x+10
3x -5+5=2x+10+5 [ adding 5 on both side]
3x=2x+15
3x-2x=2x+15-2x [subtracting 2x on both side]
x=15
Ans=15
Answer:
[tex]x = 15[/tex]
Step-by-step explanation:
[tex]3x - 5 = 10 + 2x[/tex]
[tex]3x - 2x = 10 + 5[/tex]
[tex]1x = 15[/tex]
[tex]x = 15[/tex]
Hope it is helpful.....If 19,200 cm2 of material is available to make a box with a square base and an open top, find the largest possible volume of the box.
Step-by-step explanation:
√19200cm²
=138.56cm
then the highest possible volume
=(138.56)³
=2660195.926cm³
The largest possible volume of the box is; V = 25600 cm³
Let us denote the following of the square box;
Length = x
Width = y
height = h
Formula for volume of a box is;
V = length * width * height
Thus; V = xyh
but we are dealing with a square box and as such, the base sides are all equal and so; x = y. Thus;
V = x²h
The box has an open top and as such, the surface are of the box is;
S = x² + 4xh
We are given S = 19200 cm². Thus;
19200 = x² + 4xh
h = (19200 - x²)/4x
Put (19200 - x²)/4x for h in volume equation to get;
V = x²(19200 - x²)/4x
V = 4800x - 0.25x³
To get largest possible volume, it will be dimensions when dV/dx = 0. Thus;
dV/dx = 4800 - 0.75x²
At dV/dx = 0, we have;
4800 - 0.75x² = 0
0.75x² = 4800
x² = 4800/0.75
x² = 6400
x = √6400
x = 80 cm
From h = (19200 - x²)/4x;
h = (19200 - 80²)/(4 × 80)
h = (19200 - 6400)/3200
h = 4 cm
Largest possible volume = 80² × 4
Largest possible volume = 25600 cm³
Read more at; https://brainly.com/question/19053087
Tyler and Elena are on the cross country team. Tyler’s distances and times for a training run are shown on the graph. Elenas distances and times for a training run are given by the equation y=8.5x, calculate Tyler’s pace per minute
Answer:
8.2 miles per minute
Step-by-step explanation:
Given
See attachment for graph
Required
The rate of Tyler's graph
This means that we calculate the slope (m) of the graph using:
[tex]m = \frac{y_1 - y_2}{x_1 - x_2}[/tex]
So, we have:
[tex](x_1 ,y_1) = (0,0)[/tex]
[tex](x_1 ,y_1) = (1,8.2)[/tex]
So, we have:
[tex]m = \frac{y_1 - y_2}{x_1 - x_2}[/tex]
[tex]m = \frac{0 - 8.2}{0 - 1}[/tex]
[tex]m = \frac{-8.2}{- 1}[/tex]
[tex]m = 8.2}[/tex]
using the 1 to 9 at the most time each, fill in the boxes to make a true statement
Answer:
2
Step-by-step explanation:
8*8 is 64
Since it looks like the empty box is an exponent, and there are 2 8s being multiplied, the answer is 2
Find the slope of the line that passes through the two points 2,-4 & 4,-1
Answer:
Step-by-step explanation:
I have this saved on my computer in notepad b/c this type of question get asked sooo often :/
point P1 (-4,-2) in the form (x1,y1)
point P2(3,1) in the form (x2,y2)
slope = m
m = (y2-y1) / (x2-x1)
My suggestion is copy that above and save it on your computer for questions like this
now use it
Point 1 , P1 = (2,-4) in the form (x1,y1)
Point 2 , P2 = (4,-1) in the form (x2,y2)
m = [ -1-(-4) ] / [ 4-2]
m = (-1+4) / 2
m = 3 / 2
so now we know the slope is 3/2 :)
If 2(x + 3) - 27 = 3[7 - 2(x + 19)], what is 2x - 5?
Answer:
D = -23
Step-by-step explanation:
Answer:
D) -23
Step-by-step explanation:
Definitely
a woman bought some large frames for
$12 each and some small frames for $5
each. If she bought 20 frames for $156
find how many of each type she bought.
Answer:
8 pairs of large glasses and 12 pairs of small ones
Step-by-step explanation:
Let's say the number of large frames she buys is l, and the number of small frames is s. She buys 20 frames of assorted sizes, but they can only be small or large. Therefore, s + l = 20.
Next, the total cost of large frames is 12 dollars for each frame. Therefore, the total cost for the large frames is equal to 12 * l. Similarly, the total cost for the small frames is equal to 5 * s. The total cost of all frames is equal to 156, so
12* l + 5 * s = 156
s + l = 20
In the second equation, we can subtract l from both sides to get
s = 20 - l
We can then plug that into the first equation to get
12 * l + 5 * (20-l) = 156
12 * l + 100 - 5*l = 156
subtract both sides by 100 to isolate the variable and its coefficient
12 * l - 5 * l = 56
7 * l = 56
divide both sides by 7 to isolate the l
l = 8
The woman buys 8 pairs of large glasses. The number of small glasses is equal to 20-l=20-8=12
A researcher wishes to conduct a study of the color preferences of new car buyers. Suppose that 50% of this population prefers the color green. If 14 buyers are randomly selected, what is the probability that exactly 12 buyers would prefer green
Answer:
The probability that exactly 12 buyers would prefer green
=0.00555
Step-by-step explanation:
We are given that
p=50%=50/100=0.50
n=14
We have to find the probability that exactly 12 buyers would prefer green.
q=1-p
q=1-0.50=0.50
Using binomial distribution formula
[tex]P(X=x)=nC_r p^r q^{n-r}[/tex]
[tex]P(x=12)=14C_{12}(0.50)^{12}(0.50)^{14-12}[/tex]
[tex]P(x=12)=14C_{12}(0.50)^{12}(0.50)^2[/tex]
[tex]P(x=12)=14C_{12}(0.50)^{14}[/tex]
[tex]P(x=12)=\frac{14!}{12!2!}(0.50)^{14}[/tex]
[tex]P(x=12)=\frac{14\times 13\times 12!}{12!2\times 1}(0.50)^{14}[/tex]
[tex]P(x=12)=91\cdot (0.50)^{14}[/tex]
[tex]P(x=12)=0.00555[/tex]
Hence, the probability that exactly 12 buyers would prefer green
=0.00555
Match the y coordinate with coo responding pairs of x
What is the solution set for |z+4|> 15
Answer:
I think that answer would be B.
Step-by-step explanation:
Is it possible to have a relation on the set {a, b, c} that is both symmetric and transitive but not reflexive
Answer:
Yes, it is possible to have a relation on the set {a, b, c} that is both symmetric and transitive but not reflexive
Step-by-step explanation:
Let
Set A={a,b,c}
Now, define a relation R on set A is given by
R={(a,a),(a,b),(b,a),(b,b)}
For reflexive
A relation is called reflexive if (a,a)[tex]\in R[/tex] for every element a[tex]\in A[/tex]
[tex](c,c)\notin R[/tex]
Therefore, the relation R is not reflexive.
For symmetric
If [tex](a,b)\in R[/tex] then [tex](b,a)\in R[/tex]
We have
[tex](a,b)\in R[/tex] and [tex](b,a)\in R[/tex]
Hence, R is symmetric.
For transitive
If (a,b)[tex]\in R[/tex] and (b,c)[tex]\in R[/tex] then (a,c)[tex]\in R[/tex]
Here,
[tex](a,a)\in R[/tex] and [tex](a,b)\in R[/tex]
[tex]\implies (a,b)\in R[/tex]
[tex](a,b)\in R[/tex] and [tex](b,a)\in R[/tex]
[tex]\implies (a,a)\in R[/tex]
Therefore, R is transitive.
Yes, it is possible to have a relation on the set {a, b, c} that is both symmetric and transitive but not reflexive.
Instructions: Solve the following linear
equation
4(n + 5) – 2(5 + 7n) = -70
n =
Answer:
Step-by-step explanation:
4*(n +5) - 2*(5 + 7n) = -70
4*n + 4*5 + 5*(-2) + 7n*(-2) = -70
4n + 20 - 10 - 14n = -70
4n - 14n + 20 - 10 = -70
- 10n + 10 = -70
Subtract 10 from both sides
-10n = -70 - 10
-10n = -80
Divide both sides by (-10)
n = -80/-10
n = 8
Step-by-step explanation:
sjbsbsbeekejebebheebebejekek
Can someone help me with this question an my other work?
Two cell phone companies charge a flat fee plus an added cost for each minute or part of a minute used. The cost is represented by C and the number of minutes is represented by t.
Call-More: C = 0.40t + 25 Talk-Now: C = 0.15t + 40
Answer:
The call more is cheaper than talk-now.
Step-by-step explanation:
The companies charge a flat fee plus an added cost for each minute or part of a minute used for two companies are as follows :
Call-More: C = 0.40t + 25 Talk-Now: C = 0.15t + 40
We need to find which company is cheaper if a customer talks for 50 minutes.
For call more,
C = 0.40(50) + 25 = 45 units
For talk-now,
C = 0.15(50) + 40 = 47.5 units
So, it can be seen that call more is cheaper than talk-now.
show that 43\2^4×5^3 will terminate after how many places of the decimal
Answer:
4 places after the decimal.
the result is 0.0215
Step-by-step explanation:
I assume the expression is really
43 / (2⁴ × 5³)
this is the same as
(((((((43 / 2) / 2) / 2) / 2) / 5) / 5) / 5)
since the starting value is an odd number, the first division by 2 creates a first position after the decimal point, and it must be a 5, as the result is xx.5
the second division by 2 splits again the uneven end .5 in half, creating a second position after the decimal point again ending in 5, as the result is now xx.x5
the third division by 2 does the same thing with that last 5 and creates a third position after the decimal point ending again in 5, as the result is now xx.xx5
the fourth division by 2 does again the same thing, a fourth position after the decimal point is created ending in 5. now xx.xxx5
in essence, every division of the 0.5 part by 2 is the same as a multiplication by 0.5, which squares 0.5 leading to 0.5². the next division did the same thing leading to 0.5³.
and finally the fourth division to 0.5⁴.
0.5⁴ = (5/10)⁴ = 5⁴/10⁴
so, now we start to divide this result by 5. since the positions after the decimal point are divisible by 5 without remainder, as we have 5⁴ to work with.
every divisible by 5 takes one of these powers away.
so, we go from 5⁴/10⁴ to 5³/10⁴ to 5²/10⁴ to 5/10⁴.
all the time we maintain the 10⁴ in the denominator of the fraction. and that determines the positions after the decimal point.
so, after all the individual divisions we come to and end and are still limited to the 4 positions after the decimal point.
The number of measles cases decreased by 7% to 606 cases this year. What was the number of cases prior to the increase? Express your answer rounded correctly to the nearest whole number.
Answer:
652 cases
Step-by-step explanation:
The formula for percentage increase is 100 times the final-initial/final value. If we plug the numbers in and calculate, we get 652 cases. Have a great day!
Which of the following is the intersection of the line AD and line DE?
Answer:
Point D
Step-by-step explanation:
The intersection(s) of lines represents where they cross or intersect. We can see that lines AD and DE cross or intersect as Point D, hence the answer being Point D.
Answer: Point D
Step-by-step explanation: The intersection of two figures is the set of points that is contained in both figures. In the diagram shown, D is the intersection of lines AD and DE because D is the point contained by both line AD and DE.
Consider this linear function:
y = 1/2x + 1
Plot all ordered pairs for the values in the domain.
D: {-8, -4,0, 2, 6)
9514 1404 393
Answer:
see attached
Step-by-step explanation:
The attachment shows the ordered pairs (x, f(x)) and their graph.
solve for s 9s+20=−16
Answer:
s = -4
Step-by-step explanation:
Your goal is to manipulate the equation so you can isolate s
9s + 20 = -16
Subtract 20 from both sides to get:
9s = -36
Divide both sides by 9 so s is alone
you end up with s = -4
Answer:
s = -4
Step-by-step explanation:
9s+20=−16
Subtract 20 from each side
9s +20 -20 = -16 -20
9s = -36
Divide by 9
9s/9 = -36/9
s = -4
