Answer:
a) The 60th percentile of the diameters is of 25.0177 millimeters.
b) The 67th percentile of the diameters is of 25.0308 millimeters.
c) The diameter of the hole should be of 24.8562 millimeters.
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.
Normally distributed with mean 25.0 millimeters and standard deviation 0.07 millimeter.
This means that [tex]\mu = 25, \sigma = 0.07[/tex]
(a) Find the 60th percentile of the diameters.
This is X when Z has a p-value of 0.6, so X when Z = 0.253.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]0.253 = \frac{X - 25}{0.07}[/tex]
[tex]X - 25 = 0.253*0.07[/tex]
[tex]X = 25.0177[/tex]
The 60th percentile of the diameters is of 25.0177 millimeters.
(b) Find the 67th percentile of the diameters.
This is X when Z has a p-value of 0.67, so X when Z = 0.44.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]0.44 = \frac{X - 25}{0.07}[/tex]
[tex]X - 25 = 0.44*0.07[/tex]
[tex]X = 25.0308[/tex]
The 67th percentile of the diameters is of 25.0308 millimeters.
(c) A hole is to be designed so that 2% of the ball bearings will fit through it. The bearings that fit through the hole will be melted down and remade. What should the diameter of the hole be.
This is the 2nd percentile, which is X when Z has a p-value of 0.08, so X when Z = -2.054.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-2.054 = \frac{X - 25}{0.07}[/tex]
[tex]X - 25 = -2.054*0.07[/tex]
[tex]X = 24.8562[/tex]
The diameter of the hole should be of 24.8562 millimeters.
uppose that the walking step lengths of adult males are normally distributed with a mean of 2.8 feet and a standard deviation of 0.2 feet. A sample of 76 men’s step lengths is taken. Step 1 of 2 : Find the probability that an individual man’s step length is less than 2.5 feet. Round your answer to 4 decimal places, if necessary.
Answer:
.0668
Step-by-step explanation:
Formula:
z=(x-average)/standard deviation
(2.5-2.8)/.2= -1.5
Go to a ztable and find the value for 1.5 (.9332) and take the compliment of this (we can do this because the normal distribution is symmetrical)
1-.9332= .0668
Ed decided to build a storage box. At first, he was planning to build a cubical box with edges of length n
inches. To increase the amount of storage, he decided to make the box 1 inch taller and 2 inches longer,
while keeping its depth at n inches. The volume of the box Ed built has a volume how many cubic inches
greater than the box he originally planned to build?
O 3n2 + 2n
312 + 3n+3
O 6n2 + 3n
O 6n2 + 3n+3
Given:
Edge of a cubic box = n inches.
He decided to make the box 1 inch taller and 2 inches longer, while keeping its depth at n inches.
To find:
How many cubic inches greater than the box he originally planned to build?
Solution:
Edge of a cubic box is n inches, so the volume of the original cube is:
[tex]V_1=(edge)^3[/tex]
[tex]V_1=n^3[/tex]
According to the given information,
New width of the box = n+1
New length of the box = n+2
New height of the box = n
So, the volume of the new box is:
[tex]V_2=Length\times width\times h[/tex]
[tex]V_2=(n+2)(n+1)n[/tex]
[tex]V_2=(n^2+2n+n+2)n[/tex]
[tex]V_2=(n^2+3n+2)n[/tex]
[tex]V_2=n^3+3n^2+2n[/tex]
Now, the difference between new volume and original volume is:
[tex]V_2-V_1=n^3+3n^2+2n-n^3[/tex]
[tex]V_2-V_1=3n^2+2n[/tex]
So, the volume of new box is 3n^2+2n cubic inches more than the original box.
Therefore, the correct option is A.
Help ASAP!! A triangle has side lengths of 11in, 15in, and 20in. Find the angle measures of the triangle. Round decimal answers to the nearest tenth. Someone help pls.
Answer:
<A = 47.7°
<B = 99.4°
<C = 32.9
Step-by-step explanation:
When given the measurements of all three sides, you can calculate the angles using the Cosine Law.
c² = a² + b² - 2ab cos C
(based on Pythagorean Theorem)
If we say: a = 15
b = 20
c = 11
11² = 15² + 20² - 2(15)(20) cos C
121 = 625 - 2(15)(20) cos C
121 = 625 - 600 cos C
⁻504 = ⁻600 cos C
cos⁻¹ (504 ÷ 600) = C
< C = 32.9°
a² = b² + c² - 2bc cos A
15² = 20² + 11² - 2(20)(11) cos A
225 = 521 - 2(20)(11) cos A
225 = 521 - 440 cos A
⁻296 = ⁻440 cos A
cos⁻¹ (296 ÷ 440) = A
<A = 47.7°
Then, since we know the sum of all three angles of a triangle equals 180°:
180° - 32.9° - 47.7° = 99.4°
<B = 99.4°
what is 3/2 divided by 1/8
helppp
Answer: 12
Step-by-step explanation:
The first step to dividing fractions is to find the reciprocal (reverse the numerator and denominator) of the second fraction. Next, multiply the two numerators. Then, multiply the two denominators. Finally, simplify the fractions if needed.
Find the least positive integer, written only by numbers 0, 1 and 2, which is divisible by 225.
9514 1404 393
Answer:
1,222,200
Step-by-step explanation:
A search using a computer program found ...
5432 × 225 = 1,222,200
__
1000 mod 225 = 100
4 × 225 = 900
This suggests that if we have some number of thousands whose digits total 9, that we will have the number of interest. Of course, we can add 200 to some number of thousands with a digit total of 7. The smallest such digit total will be had with the number 1222 using the specified digits {0, 1, 2}. This gives rise to the result above: 1222×1000 +200 = 1,222,200. It also explains why moving the 1 to the right will also give a multiple of 225.
A walking path across a park is represented by the equation y = -4x + 10. A new path will be built perpendicular to this path. The paths will intersect at the point (4, -6). Identify the equation that represents the new path.
Answer: [tex]y=\frac{1}{4}x-7[/tex]
Step-by-step explanation:
The perpendicular slope of the line(m) = [tex]-\frac{1}{m}[/tex]:
m = -4 ⇒ [tex]-\frac{1}{m} =-\frac{1}{(-4)} =\frac{1}{4}[/tex]The function formula is y = mx + b, where the y-intercept(b) is found by substituting in the values of a point on the line ⇒ (4, -6):
[tex]y=\frac{1}{4}x+b\\-6=\frac{1}{4}(4)+b\\-6=1+b\\b=-6-1=-7[/tex]
So the perpendicular equation is [tex]y=\frac{1}{4}x-7[/tex].
Based on the diagram, what is cos A?
Enter your answer in the boxes.
COS A=
[tex] cos(A) = \frac{ {b}^{2} + {c}^{2} - {a}^{2} }{2bc} [/tex]
The cos A will be b/c
Cosine functionCosine function in a triangle is the ratio of the adjacent side to that of the hypotenuse
How to solve this problem?The steps are as follow:
Given,AB = c
BC = a
AC = b
AB is hypotenous whereas AC is adjacent side to AAccording to formula of cos,Cos A = Adjacent side to A / Hypoteneous
Cos A = AC / AB
Cos A = b / c
Therefore the value of Cos A in given figure will be b / c
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from the given illustration at the right the law of sines cannot be used since
Answer:
D. No angle opposite the sides is given
Step-by-step explanation:
Given
See attachment for triangle
Required
Why the law of sines cannot be used
From the attached image of a triangle, we can see that all sides are given while none of the angles are given.
Since none of the angles are given, then law of sines doesn't apply
why was it difficult for the woman to cross the road
Given: triangle ABC with side lengths a, b, and c, and height h
Prove: Area = 1/2absin C
Answer:
Step-by-step explanation:
Statements Reasons
1). ΔABC with side lengths a, b, c, and h 1). Given
2). Area = [tex]\frac{1}{2}bh[/tex] 2). Triangle area formula
3). [tex]\text{sin}C=\frac{h}{a}[/tex] 3). Definition of sine
4). asin(C) = h 4). Multiplication property of
equality.
5). Area = [tex]\frac{1}{2}ba\text{sin}C[/tex] 5). Substitution property
6). Area = [tex]\frac{1}{2}ab\text{sin}C[/tex] 6). Commutative property of
multiplication.
Hence, proved.
Two different businesses model their profits over 15 years, where x is the year, f(x) is the profits of a garden shop, and g(x) is the profits of a construction materials business. Use the data to determine which function is exponential, and use the table to justify your answer.
1. f(x) is exponential; an exponential function increases more slowly than a linear function.
2. f(x) is exponential; f(x) increased more overall than g(x).
3. g(x) is exponential; g(x) has a higher starting value and higher ending value.
4. g(x) is exponential; an exponential function increases faster than a linear function.
Hi there!
[tex]\large\boxed{\text{Choice 4}}[/tex]
We can look at each function, f(x) and g(x), to determine which is exponential.
Use slope formula: m = y2-y1/x2-x1
f(x) starts off with a slope at about $1800/year, but becomes about $1100/year.
g(x) starts off with a slope of about $1500/year, but becomes about $1874/year.
Thus, g(x) is exponential, because g(x)'s slope is increasing across the interval.
You want to send postcards to 15 friends. In the shop there are only 3 kinds of postcards. In how many ways can you send the postcards, if
Answer:
455 ways
Step-by-step explanation:
Given
[tex]n = 15[/tex] --- friends
[tex]r = 3[/tex] -- available postcard kinds
Required
Ways of sending the cards
The question is an illustration of combination and the formula is:
[tex]^nC_r = \frac{n!}{(n - r)!r!}[/tex]
So, we have:
[tex]^{15}C_3 = \frac{15!}{(15 - 3)!3!}[/tex]
[tex]^{15}C_3 = \frac{15!}{12!*3!}[/tex]
Expand
[tex]^{15}C_3 = \frac{15*14*13*12!}{12!*3*2*1}[/tex]
[tex]^{15}C_3 = \frac{15*14*13}{3*2*1}[/tex]
[tex]^{15}C_3 = \frac{2730}{6}[/tex]
[tex]^{15}C_3 = 455[/tex]
is -3 linear pls help
Answer:
Yes it is. Graph will go down as it moves from left to right.
Step-by-step explanation:
I need help with this, please.
Answer:
it can not cleared clear but it can not cleared
when a number is added to 1/5 of itself, the result is 24. the equation that models this problem is n+1/5n=24. what is the value of n?
1. Mary got the following scores: 83, 88, 78, 80, and 90 in her examination in English. What is the mean score of Mary?
A. 83.08
B. 83.8
C. 88.38
D. 88.83
2. A list of 5 pulse rates: 70, 64, 80, 74, and 92. Which of the following is the median for this list? *
A. 80
B. 77
C. 76
D. 74
3. After checking the summative test of her 50 students, Teacher Rose found out that most of her students got 38 correct answers out of 50-item test. Which measure of central tendency do 38 represent?
A. frequency
B. median
C. mode
D. range
4. Mary found out that the difference between her highest score and lowest score in the first periodic test is 27. What measure of variability did she use?
A. range
B. mean
C. class size
D. class interval
5. What is the average deviation of the scores 5, 4, 3, 6, and 2?
A. 3.5
B. 3
C. 2.5
D. 1.2
6. If the range of the grouped data is 30 and the lower class boundary is 64.5, which of the following is the upper class boundary of the distribution?
A. 84.5
B. 85.5
C. 90.5
D. 94.5
If you have the variance, how do you get the standard deviation?
A. Square it
B. Take the square root
C. Take the reciprocal
D. Divide it by the sample size
7. If the standard deviation is 14.3, which of the following is the variance?
A. 204.49
B. 104.5
C. 28.6
D. 24.94
please answer this guys, i really need your help.
Answer:
1=83.08
Step-by-step explanation:
mean=summation of number divided by number
How many solutions are there for the system of nonlinear equations
represented by this graph?
10
8
0
4
2
-
BE
-10-8
-6
0
-2
-2
2
4
8
10
4
-
-8
-10
O A. Two
O B. None
C. One
Help! please don't just steal my pointss
Answer:
hi, option C is correct because it has a right angel. please give brainliest
8. The point in a distribution below which 75% of the cases lie in the?
A 3rd decile
B. 7th percentile C. 3rd quartile D. 1st quartile
Answer:
C. 3rd quartile
Step-by-step explanation:
Percentile:
A data belonging to the xth percentile means that the data is greater than x% of the values of the data-set, and smaller than (100 - x)%.
Point below 75% of the cases lie:
This is the 75th percentile, which is the 3rd quartile, as 75 = 3*100/4. Thus, the correct answer is given by option c.
In a test of a heat-seeking rocket, a first rocket is launched at 2000 fts and the heat-seeking rocket is launched along the same flight path 20 s later at a speed of 3000 fts. Find
the timest, and t, of flight of the rockets until the heat-seeking rocket destroys the first rocket
What are the times of the flight?
Answer:
Time of flight of first rocket = 60 seconds
Time of flight of second rocket = 40 seconds
Step-by-step explanation:
Let the time of flight of first rocket be t1.
Since the second rocket is launched 20 seconds later, then it means that;
t1 = t2 + 20
Where t2 is the time of flight of the second rocket.
When destruction has occurred, it means that both of the rockets would have covered the same distance.
We know that;
Distance = speed × time
Thus;
2000t1 = 3000t2
We know that t1 = t2 + 20
Thus;
2000(t2 + 20) = 3000t2
2000t2 + 40000 = 3000t2
3000t2 - 2000t2 = 40000
1000t2 = 40000
t2 = 40000/1000
t2 = 40 seconds
Thus;
t1 = 40 + 20
t1 = 60 seconds
Translate the following into an algebraic expression: If it would take Mark m hours to clean the house alone and with his brother Sam they can clean the house together in t hours. How many hours would it have taken Sam if he was working alone
A closed, rectangular-faced box with a square base is to be constructed using only 36 m2 of material. What should the height h and base length b of the box be so as to maximize its volume
Answer:
[tex]b=h=\sqrt{6}[/tex] m
Step-by-step explanation:
Let
Bas length of box=b
Height of box=h
Material used in constructing of box=36 square m
We have to find the height h and base length b of the box to maximize the volume of box.
Surface area of box=[tex]2b^2+4bh[/tex]
[tex]2b^2+4bh=36[/tex]
[tex]b^2+2bh=18[/tex]
[tex]2bh=18-b^2[/tex]
[tex]h=\frac{18-b^2}{2b}[/tex]
Volume of box, V=[tex]b^2h[/tex]
Substitute the values
[tex]V=b^2\times \frac{18-b^2}{2b}[/tex]
[tex]V=\frac{1}{2}(18b-b^3)[/tex]
Differentiate w. r.t b
[tex]\frac{dV}{db}=\frac{1}{2}(18-3b^2)[/tex]
[tex]\frac{dV}{db}=0[/tex]
[tex]\frac{1}{2}(18-3b^2)=0[/tex]
[tex]\implies 18-3b^2=0[/tex]
[tex]\implies 3b^2=18[/tex]
[tex]b^2=6[/tex]
[tex]b=\pm \sqrt{6}[/tex]
[tex]b=\sqrt{6}[/tex]
The negative value of b is not possible because length cannot be negative.
Again differentiate w.r.t b
[tex]\frac{d^2V}{db^2}=-3b[/tex]
At [tex]b=\sqrt{6}[/tex]
[tex]\frac{d^2V}{db^2}=-3\sqrt{6}<0[/tex]
Hence, the volume of box is maximum at [tex]b=\sqrt{6}[/tex].
[tex]h=\frac{18-(\sqrt{6})^2}{2\sqrt{6}}[/tex]
[tex]h=\frac{18-6}{2\sqrt{6}}[/tex]
[tex]h=\frac{12}{2\sqrt{6}}[/tex]
[tex]h=\sqrt{6}[/tex]
[tex]b=h=\sqrt{6}[/tex] m
A car and a motorcycle whose average rates are in the ratio of 4:5 travel a distance of 160 miles. If the motorcycle
travels 1/2 hour less than the car, find the average rate of each.
Answer:
Step-by-step explanation:
I always advise my students to make a table of information for these story problems because trying to keep track of the information otherwise is a nightmare. The table will look like this:
d = r * t
m
c
m is motorcycle and c is car.
First thing we are told is that the ratio of m's speed to c's speed is 5:4; that means that we can divide 5/4 to find out how many times faster m is going than c.
5/4 = 1.25 so we have a couple of values to put into the table right away, along with the fact that they are both traveling the same distance of 160 miles.
d = r * t
m 160 = 1.25r
c 160 = r
The last thing we have to fill in is the time. If m travels a half hour less than c, c is driving a half hour more than m, right? Filling that in:
d = r * t
m 160 = 1.25r * t
c 160 = r * t + .5
Now we have our 2 equations. Looking at the top row of the table gives us the formula we need to solve this problem. It tells us, in other words, what we are going to be doing with these columns of numbers. Distance equals the rate times the time. For the motorcycle, the equation is:
160 = (1.25r)t and that seems pretty useless since we still have 2 unknowns in there and you can only have 1 unknown in 1 equation. Let's see what the equation for the car is.
160 = (t + .5)r Same problem.
Let's go back to the equation for the motorcycle and since we are looking for the rates of each, let's solve that equation for time in terms of rate (solve it for t):
[tex]t=\frac{160}{1.25r}[/tex] and sub that into the car's equation in place of t:
[tex]160=r(\frac{160}{1.25r})+.5r[/tex] and simplify. The r's to the left of the plus sign cancel out leaving us with:
[tex]160=(\frac{160}{1.25})+.5r[/tex] and divide those numbers inside the parenthesis to get:
160 = 128 + .5r and subtract 128 from both sides to get:
32 = .5r and finally divide by .5 to get
r = 64 miles/hour
The car goes 64 mph and the motorcycle goes 1.25 times that so,
m = 1.25(64) and
m = 80 mph
You and Michael have a total of $19.75. If Michael has $8.25, how much
money do you have?
$27.00
$28.00
$11.50
$12.00
Answer:
You have a total of $11.50
Step-by-step explanation:
We first subtract $19.75 by $8.25 and the result will be $11.50
Answer:
11.50
Step-by-step explanation:
19.75-8.35= 11.50
May I have the brainiest?
F(x) =-2x-4 find x if f(x)=14
Answer:
14=-2x-4
18=-2x
x=-9
Hope This Helps!!!
Which statement best compares the two functions? The minimum of function A occurs 1 unit higher than the minimum of function B. The minimum of function A occurs 3 units higher than the minimum of function B. The minimum of function A occurs 5 units lower than the minimum of function B. The minimum of function A occurs 7 units lower than the minimum of function B.
Answer: D: The minimum value of A occurs 7 units lower than minimum of function B.
Step-by-step explanation: The minimum of function A is at (3,-2), while the minimum of function B would be at (-3,5). So, you do 5-(-2) to get 7.
The minimum value of A occurs 7 units lower than the minimum of function B.
We have given that,
Statement best compares the two functions
What is the minimum and maximum function?
The maxima and minima of a function, known collectively as extrema, are the largest and smallest value of the function, either within a given range, or on the entire domain.
The minimum of function A is at (3,-2), while the minimum of function B would be at (-3,5). So, you do 5-(-2) to get 7.
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The weight of a newborn is 7.5 pounds. The baby gained one-half pound a month constantly for its first year.
a) Find the linear function that models the baby’s weight, W, as a function of the age of the baby, in
months, t.
b) Find a reasonable domain and range for the function W.
c) If the function W is graphed, find and interpret the x- and y-intercepts.
d) If the function W is graphed, find and interpret the slope of the function.
e) When did the baby weight 10.4 pounds?
f) What is the output when the input is 6.2? Interpret your answer.
3. Of 1000 randomly selected cases of lung cancer, 450 resulted in death within 5 years. Calculate a 96% CI on the death rate from lung cancer.
Answer:
The 96% CI on the death rate from lung cancer is (0.4177, 0.4823).
Step-by-step explanation:
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 z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
Of 1000 randomly selected cases of lung cancer, 450 resulted in death within 5 years.
This means that [tex]n = 1000, \pi = \frac{450}{1000} = 0.45[/tex]
96% confidence level
So [tex]\alpha = 0.04[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.04}{2} = 0.98[/tex], so [tex]Z = 2.054[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.45 - 2.054\sqrt{\frac{0.45*0.55}{1000}} = 0.4177[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.45 + 2.054\sqrt{\frac{0.45*0.55}{1000}} = 0.4823[/tex]
The 96% CI on the death rate from lung cancer is (0.4177, 0.4823).
ANSWER QUICKLY!!! What is the median of Restaurant B's cleanliness ratings?
4
3
1
5
2
A square coffee shop has sides that are 10 meters long. What is the coffee shop's area?
square meters
100
SOLUTION:
10•10= 100
