wo men, A and B, who usually commute to work together decide to conduct an experiment to see whether one route is faster than the other. The men feel that their driving habits are approximately the same, so each morning for two weeks one driver is assigned to route I and the other to route II. The times, recorded to the nearest minute, are shown in the following table. Using this data, find the 98%98%confidence interval for the true mean difference between the average travel time for route I and the average travel time for route II.
Let d=(route I travel time)−(route II travel time)d=(route I travel time)−(route II travel time). Assume that the populations of travel times are normally distributed for both routes.
Day | M | Tu | W | Th | F | M | Tu | W | Th | F |
---|---|---|---|---|---|---|---|---|---|---|
Route I | 32 | 25 | 27 | 32 | 28 | 31 | 32 | 31 | 28 | 32 |
Route II | 31 | 23 | 26 | 27 | 25 | 33 | 31 | 27 | 27 | 33 |
Step 1 of 4: Find the mean of the paired differences, d‾‾. Round your answer to one decimal place.
Step 2 of 4: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.
Step 3 of 4: Find the standard deviation of the paired differences to be used in constructing the confidence interval. Round your answer to one decimal place.
Step 4 of 4: Construct the 98% confidence interval. Round your answers to one decimal place.
....lower endpoint...upper endpoint
In: Math
The World Health Organization (WHO) keeps track of how many incidents of leprosy there are in the world. Using the WHO regions and the World Banks income groups, onc can sask if an income level and a WHO region are dependent on each other in terms of predicting where the disease is. Data on leprosy cases in different countries was collected for hte year 2011 and a summary is present in the following table.
WHO Region: |
World Bank Income Group: |
Row Total |
|||
High Income |
Upper Middle Income |
Lower Middle Income |
Low Income |
||
Americas |
174 |
36028 |
615 |
0 |
36817 |
Eastern Mediterranean |
54 |
6 |
1883 |
604 |
2547 |
Europe |
10 |
0 |
0 |
0 |
10 |
Western Pacific |
26 |
216 |
3689 |
1155 |
5086 |
Africa |
0 |
39 |
1986 |
15928 |
17953 |
South-East Asia |
0 |
0 |
149896 |
10236 |
160132 |
Column Total |
264 |
36289 |
158069 |
27923 |
222545 |
In: Math
In how many ways can 2 men, 4 women, 3 boys, and 3 girls be selected from 6 men, 8 women, 4 boys and 5 girls if a particular man and woman must be selected?
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Describe: (1) every component of the equation for calculating a correlation coefficient; (2) the purpose of each component; (3) what kind of data you would use this equation on; and (4) how to use the equation on raw data.
In: Math
In the US I want to know what proportion of 13-year-olds vape. Three distributions are associated with this question: population distribution, sample distribution, and sampling distribution. Describe the role of each in answering this question.
In cross-sectional analysis explain why it is necessary to take a random sample.
Describe the difference between an estimator and an estimate and explain why estimators are random variables while estimates are not.
Explain why point estimates are always wrong.
In: Math
Discuss the applications of ANOVA (One-Way ANOVA, Two-Way ANOVA) and regression techniques in the context of e-commerce firms like Amazon, Flipkart etc.
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Let X and Z be two independently distributed standard normal random variables and let Y=X2+Z.
iShow thatE(Y|X) =X2
iiShow thatμY= 1
iiiShow thatE(XY) = 0ivShow that cov(X,Y) = 0 and thus ρX,Y= 0
In: Math
For this problem, carry at least four digits after the decimal
in your calculations. Answers may vary slightly due to
rounding.
In a marketing survey, a random sample of 1010 supermarket shoppers
revealed that 266 always stock up on an item when they find that
item at a real bargain price.
(a)
Let p represent the proportion of all supermarket
shoppers who always stock up on an item when they find a real
bargain. Find a point estimate for p. (Enter a number.
Round your answer to four decimal places.)
(b)
Find a 95% confidence interval for p. (For each answer,
enter a number. Round your answers to three decimal places.)
lower limit
upper limit
Give a brief explanation of the meaning of the interval.
5% of all confidence intervals would include the true proportion of shoppers who stock up on bargains
95% of the confidence intervals created using this method would include the true proportion of shoppers who stock up on bargains.
5% of the confidence intervals created using this method would include the true proportion of shoppers who stock up on bargains.
95% of all confidence intervals would include the true proportion of shoppers who stock up on bargains.
(c)
As a news writer, how would you report the survey results on the percentage of supermarket shoppers who stock up on items when they find the item is a real bargain?
Report the margin of error.
Report p̂.
Report p̂ along with the margin of error.
Report the confidence interval.
What is the margin of error based on a 95% confidence interval?
(Enter a number. Round your answer to three decimal places.)
In: Math
Two rolls of a fair die. Let x and y be the results of the two rolls, and let z = x + y.
(a) Find P[x = 4, y = 3], P[x > 3, y = 5].
(b) Find P[z = 7], P[z = 5], P[z = 3].
(c) Find the probability that at least one 6 appears given that z = 8.
(d) Find the probability that x = 6 given that z > 8.
(e) Find the probability that z = 7 given that at least one 4 was rolled. (f) Find the probability that z > 7 given that y = 4.
In: Math
What is the level measurement of the following Operational Definitions. i.e., Nominal, Ordinal or Interval level data?
1 The unemployment rates of the 50 states.
2 The region of country in which people were born
3 How frequently people attended religious services in the last two months.
4 The number of employees in different government agencies.
5 The number of times incumbent senators voted the way the president wanted them to vote on key pieces of legislation.
6 The occupation of candidates for public office (i.e. educator, lawyer, farmer, business person).
7 The percent of different corporations’ pretax profit accounted for by overseas sales.
8 Whether people read the daily newspaper every day, almost every day, frequently, occasionally, seldom, or never.
In: Math
Gregor Mendel established the concept of dominant and recessive genes and characteristics. According to Mendel’s law when crossing two inbred lines, 75% of the offspring should show dominant and 25% recessive characteristics. In his 19th century work studying inheritance of seed form in peas, Mendel observed 7,324 individuals, 5,474 of which had dominant characteristics.
a. Does this support or contradict Mendel’s law? Explain.
b. If the observation would be 5,566 (out of 7,324), would it be likely that his conjecture is true, i.e., 75% percent would show dominant characteristics? Explain.
In: Math
Allele frequency is the relative frequency of a certain allele type among a certain population. Suppose that within a certain area, the allele frequency of A, B and O are 0.2, 0.1, and 0.7, respectively. Suppose that when randomly picking up a person, the first allele type is independent of the second allele type regardless of the type. Calculate the following probabilities:
• The probability for this person to have type O blood.
• The probability for this person to have type A blood.
• The probability for this person to have type B blood.
• The probability for this person to have type AB blood.
In: Math
When purchasing bulk orders of batteries, a toy manufacturer uses this acceptance sampling plan: Randomly select and test 42 batteries and determine whether each is within specifications. The entire shipment is accepted if at most 3 batteries do not meet specifications. A shipment contains 3000 3000 batteries, and 3% of them do not meet specifications. What is the probability that this whole shipment will be accepted? Will almost all such shipments be accepted, or will many be rejected?
In: Math
A survey reported that 37% of people plan to spend more on eating out after they retire. If
eight people are randomly selected, determine the values below.
a. |
The expected number of people who plan to spend more on eating out after they retire |
b. |
The standard deviation of the individuals who plan to spend more on eating out after they retire |
c. |
The probability that two or fewer in the sample indicate that they actually plan to spend more on eating out after retirement |
In: Math
Consider the quarterly electricity production for years 1-4: Year 1 2 3 4 Q1 99 120 139 160 Q2 88 108 127 148 Q3 93 111 131 150 Q4 111 130 152 170 (a) Estimate the trend using a centered moving average. (b) Using a classical additive decomposition, calculate the seasonal component. (c) Explain how you handled the end points. Note: Explain all the steps and computations in your own words and it should be typed on Microsoft word .
In: Math