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Question 1177608: The times spent by people visiting a certain dentist are independent and normally distributed with a mean of 8.2 minutes. 79% of people who visit this dentist have visits lasting less than 10 minutes.
Find the probability that, of 35 randomly chosen people, fewer than 16 have visits lasting
less than 8.2 minutes.
(answer = 0.250)
Click here to see answer by CPhill(1959)   |
Question 1177476: There are 150 people at an International
Medical Conference. 40 are Africans, 70
are women and 110 are doctors. 12 of the
women are Africans, 46 of the doctors are
women and 31 of the Africans are doctors.
If 5 of the African men are not doctors:
a how many of the African women are
doctors
b how many of the men are neither African
nor doctors?
Click here to see answer by CPhill(1959) |
Question 1177418: A helicopter carrying Dr. Evil takes off with a constant upward acceleration of 7.0 m/s^2.
Secret agent Austin Powers jumps on just as the helicopter lifts off the ground. After the two men struggle for 12.0 s, Powers shuts off the engine and steps out of the helicopter.
Assume that the helicopter is in free-fall after its engine is shut off, and ignore the effects of air resistance.
(a) What is the maximum height above ground reached by the helicopter?
(b) Powers deploys a jet pack strapped on his back 7.0 s after leaving the
helicopter, and then he has a constant downward acceleration with magnitude 2.0 m/s^2.
How far is Powers above the ground when the helicopter crashes into the ground?
Click here to see answer by CPhill(1959) |
Question 1177278: At a construction site, the daily requirement of gneiss
(in metric tons) is a random variable having a gamma distribution with α = 2 and β = 5. If their supplier’s
daily supply capacity is 25 metric tons, what is the
probability that this capacity will be inadequate on
any given day?
Click here to see answer by CPhill(1959) |
Question 1176722: A wireless carrier offers the following plans that a person is considering.
The Family Plan: $90 monthly fee, unlimited talk and text on up to 8 lines, and data charges of $40 for each device for
up to 2 GB of data per device. The Mobile Share Plan: $120 monthly fee for up to 10 devices, unlimited talk and text
for all the lines, and data charges of $35 for each device up to a shared total of 10 GB of data. Use P for the number of
devices that need data plans as part of their cost.
Find the model of the total cost of the Family Plan
Click here to see answer by CPhill(1959) |
Question 1176641: A manufacturer of ski clothing makes ski pants and ski jackets. The profit on a pair of ski pants is $2.00 and the profit on a jacket is $1.50. Both pants and jackets require the work of sewing operators and cutters. There are 60 minutes of sewing operator time and 48 minutes of cutter time available. It takes 8 minutes to sew one pair of ski pants and 4 minutes to sew one jacket. Cutters take 4 minutes on pants and 8 minutes on a jacket.
Find the number of pants and jackets the manufacturer should make in order to maximize the profit.
? pairs of pants
? jackets
What is the maximum profit? $
Click here to see answer by CPhill(1959) |
Question 1175395: A spheroid (or oblate spheroid) is the surface obtained by rotating an
ellipse around its minor axis. The bowl in Figure 1.41 is in the shape of
the lower half of a spheroid; that is, its horizontal cross sections are
circles while its vertical cross sections that pass through the center are
semi-ellipses. If this bowl is 10 in wide at the opening and V10 in deep
at the center, how deep does a circular cover with diameter 9 in go into
the bowl?
Click here to see answer by CPhill(1959) |
Question 1174678: The manager of the credit department for an oil company would like to determine whether the average monthly balance of credit card holders is higher than P3,000. An auditor randomly samples 150 accounts and finds that the average owed is P4170 with a standard deviation of P1,182.50. Using the 0.05 level of significance, can the auditor conclude that there is evidence that the average monthly balance is really higher than P3,000?
Click here to see answer by CPhill(1959) |
Question 1173635: Measuring the height of a Yellow Meranti is very difficult because these trees grow to heights over 300 feet. In 2016, a group of Yellow Meranti in Sabah’s Danum Valley was announced as the tallest tropical trees in the world. People familiar with these trees understand that the height of a Yellow Meranti is related to other characteristics of the tree, including the diameter of the tree at the breast height of a person (in inches) and the thickness of the bark of the tree (in inches). The file YellowMeranti contains the height, diameter at breast height of a person, and bark thickness for a sample of 40 Yellow Meranti trees.
Height : 134,213,183,90,147,110,190,89,165,124,92,180,224,191,175,253,246,237,253,210,233,122,194,167,82,134,100,173,81,150,113,84,164,203,174,159,230,224,215,230.
Diameter at breast height: 24,30,22,12,28,33,56,12,29,13,14,56,47,33,20,46,50,57,43,37,10,22,27,20,11,25,30,51,11,26,12,13,51,43,30,18,42,45,52,39.
Bark thickness: 1.2,3.1,2.2,1.3,2.2,1.5,2,1.2,2.8,1.7,1.5,2.5,2.2,2.8,3.3,2.9,4.7,4.42.4,3.9,1.5,1.1,2.8,2,1.2,2,1.4,1.8,1.1,2.5,1.5,1.4,2.3,2,2.5,3,2.6,4.3,4,2.2
a. State the single linear regression models where the height of Yellow Meranti is treated as the response or dependent variable while:
- the diameter of the tree at the breast height of a person (in inches) is the sole explanatory or independent variable. (1 Marks)
- the thickness of the bark of the tree (in inches) is the sole explanatory or independent variable. (1 Marks)
b. Based on the ordinary least square estimate, calculate the estimated slope (b_1) and the intercept (b_0) when:
- the diameter of the tree at the breast height of a person (in inches) is the sole explanatory or independent variable. (4 Marks)
- the thickness of the bark of the tree (in inches) is the sole explanatory or independent variable. (4 Marks)
c. State the multiple linear regression model where the height of Yellow Meranti is treated as the dependent variable while the diameter and bark thickness of the tree are the explanatory variables. (2 Marks)
d. Based on relevant statistical software, determine the multiple linear regression equation for (c) and show the output of the software. (4 Marks)
e. By referring to the p-value, determine whether the diameter and bark thickness of Yellow Meranti are significant in explaining its heights. (2 Marks)
f. Predict the height of the Yellow Meranti when the diameter of the tree at breast height of a person is 20 inches while the bark thickness is 4.4 inches. (2 Marks)
Click here to see answer by CPhill(1959) |
Question 1173255: a. A chi-square goodness of fit test, a chi-square independence test, or a chi-square homogeneity test is always right-tailed. Why?
b. Suppose you are conducting chi-square goodness of fit test. If the sum of the expected frequencies does not equal the sample size, what do you conclude?
Click here to see answer by CPhill(1959) |
Question 1173050: The Jackson’s gross monthly income is $6500. They have 13 remaining payments of $320 on a new car and 6 remaining payments of $76 on a washer and dryer. The taxes and insurance on the house are $125 per month. What maximum monthly payment does the banks loan officer feel that the Jackson’s can afford?
$1820.00
$1854.00
$1709.12
$1730.40
Click here to see answer by CPhill(1959) |
Question 1173049: Sheila little has a gross monthly income of $3500. She has 15 remaining payments of $147 on a used car. The taxes and insurance on the house are $85 per month. What maximum monthly payment does the banks loan officer feel that Sheila can afford?
2416.16
980.00
938.84
838.25
Click here to see answer by CPhill(1959) |
Question 1171429: 11. Can you find the plaintext that produced the ciphertext below? A shift cipher with undisclosed
encryption key was used.
UEUFXGZOTFUYQKQF
12. Below is ciphertext produced by a shift cipher with undisclosed encryption key. Decrypt it using
frequency analysis.
WIVHLVETPRERCPJZJTRESVLJVUFEFKYVIKPGVJFWTZGYVIJKFFSLKZKZJEFKLJLR
CCPRJJZDGCVRJZKZJNZKYJYZWKTZGYVIJDREPFWKYVJVFKYVITZGYVIJNZCCR
GG VRIYVIVZEKYVEVOKWVNDFEKYJ
Click here to see answer by ikleyn(52777)  |
Question 1171735: The corporate and strategic department has decided to add exactly 200 km of
highway and exactly 100 km of expressway to its road system this year. The
standard price for road construction is RM1 million per kilometer of highway and
RM5 million per kilometer of expressway. Only two contractors, company ABC and
company RST, are eligible to proceed with the construction, so the entire 300 km of
road must be built by these two companies.
However, company ABC can construct at most 200 km of roadway (highway and
expressway) and company RST can construct at most 150 km of roadway (highway
and expressway). Each company must be awarded a contract with a standard price
of at least RM250 million (before discounts).
Company ABC offers a discount of RM10,000 per km of highway and RM60,000 per
km of expressway. Meanwhile company RST offers a discount of RM20,000 per km
of highway and RM50,000 per km of expressway
a. Construct the formulas for the problem above by using 𝑥 for highway and 𝑦 for
expressway. Find the total discount to be named as D, received from both
companies in Ringgit Malaysia.
[15 marks]
b. The corporate and strategic department targets to maximize the total discount,
D. List out the SIX (6) constraints involved and evaluate the values of 𝑥 and 𝑦
that will maximize D.
[35 marks]
Click here to see answer by CPhill(1959) |
Question 1171472: In Statistics, there are FOUR (4) levels of measurements on data.
a) By using your own words, explain the concept of each measurement level of data.
b) Compare and contrast thoroughly each measurement level of data with the use of examples in the context of college life to demonstrate your understanding.
Click here to see answer by CPhill(1959) |
Question 1170715: Mrs. Ramos sold twice as many butter
cookies as chocolate chip cookies and
twice as many chocolate chip cookies as
coconut cookies. Each cookie was sold
for 9 peso. Each box of 6 cookies was sold
for 45 peso. If she sold 80 chocolate chip
cookies, how much did Mrs. Ramos earn
from the sale of all the cookies?
Click here to see answer by CPhill(1959) |
Question 1170572: Let F be a field of characteristic 0 and let
W = ( A = [a_ij] ∈ F^(n×n) : tr(A) = ∑_(i=1)^n▒a_ii = 0) .
For i,j = 1,…, n with i≠j , let E_ij be the n×n matrix with (i, j)-th entry 1 and all the remaining entries 0. For i =2,…,n let E_i be the n×n matrix with (1, 1) entry −1, (i,i)-th entry +1 , and all remaining entries 0. Let S = {E_ij : i,j = 1,…, n and i≠j} ∪ {E_i : i = 2,…, n} .
[Note: You can assume, without proof, that S is a linearly independent subset of F^(n×n).]
(1) Prove that W is a subspace of F^(n×n) and that W = span(S) . What is the dimension of W ?
(2) Suppose that f is a linear functional on F^(n×n) such that
(a) f(AB) = f(BA) , for all A, B ∈F^(n×n) .
(b) f(I) = n , where I is the identity matrix in F^(n×n) .
Prove that f(A) = tr(A) for all A ∈ F^(n×n)
Click here to see answer by CPhill(1959) |
Question 1170302: A medical test has been designed to detect the presence of a certain disease. Among those who
have the disease, the probability that the disease will be detected by the test is 0.96. However,
the probability that the test will erroneously indicate the presence of the disease in those who
do not actually have it is 0.03. It is estimated that 95% of the population who take this test do
not have the disease.
a. Construct a tree diagram for the above information.
b. If a test is administered to an individual, what is the probability that the test is positive?
c. If a test administered to an individual is negative, what is the probability that the person
actually has the disease?
Click here to see answer by CPhill(1959) |
Question 1170091: In a test of the effectiveness of garlic for lowering cholesterol, 43 subjects were treated with garlic in a processed tablet form. Cholesterol levels were measured before and after the treatment. The changes (beforeafter) in their levels of LDL cholesterol (in mg/dL) have a mean of 5.7 and a standard deviation of 17.9. Construct a 99% confidence interval estimate of the mean net change in LDL cholesterol after the garlic treatment. What does the confidence interval suggest about the effectiveness of garlic in reducing LDL cholesterol?
Click here to see answer by CPhill(1959) |
Question 1167591: A man will deposit with a trust company a sum just sufficient to provide his family with an annuity of 750 dollars per month for 15 years. How much does he deposit if the fund accumulates at {4 1/2%, m=12}?
Click here to see answer by ikleyn(52777) |
Question 1167306: The velocity function(in meters per second) for a particle moving along a line is given by v(t)=cost
a. Graph the velocity from t=0 to t=2pi
B. Find the displacement of the particle from t=0 to t=pi
C. Find the total distance traveled by the particle from t=0 to t=pi
Click here to see answer by ikleyn(52777) |
Question 1165638: In a chess tournament, Benny has scored five wins out of 12 rounds. He would like to increase his winning percentage up to at least 65%. At least how many rounds of games should he score/win to bring up his average winning percentage to 65%?
Click here to see answer by ikleyn(52777) |
Question 1168548: 3. Marginal cost. Suppose the daily cost, in hundreds of
dollars, of producing x security systems is
C1x2 = 0.002x3 + 0.1x2 + 42x + 300,
and currently 40 security systems are produced daily.
a) What is the current daily cost?
b) What would be the additional daily cost of increasing
production to 41 security systems daily?
c) What is the marginal cost when x = 40?
d) Use marginal cost to estimate the daily cost of increasing
production to 42 security systems daily.
Click here to see answer by CPhill(1959) |
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11161..11205, 11206..11250, 11251..11295, 11296..11340, 11341..11385, 11386..11430, 11431..11475, 11476..11520, 11521..11565, 11566..11610, 11611..11655, 11656..11700, 11701..11745, 11746..11790, 11791..11835, 11836..11880, 11881..11925, 11926..11970, 11971..12015, 12016..12060, 12061..12105, 12106..12150, 12151..12195, 12196..12240, 12241..12285, 12286..12330, 12331..12375, 12376..12420, 12421..12465, 12466..12510, 12511..12555, 12556..12600, 12601..12645, 12646..12690, 12691..12735, 12736..12780, 12781..12825, 12826..12870, 12871..12915, 12916..12960, 12961..13005, 13006..13050, 13051..13095, 13096..13140, 13141..13185, 13186..13230, 13231..13275, 13276..13320, 13321..13365, 13366..13410, 13411..13455, 13456..13500, 13501..13545, 13546..13590, 13591..13635, 13636..13680, 13681..13725, 13726..13770, 13771..13815, 13816..13860, 13861..13905, 13906..13950, 13951..13995, 13996..14040, 14041..14085, 14086..14130, 14131..14175, 14176..14220, 14221..14265, 14266..14310, 14311..14355, 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