Explain the different hypothesis tests one could use when assessing the distribution of a categorical variable (e.g. smoking status) with only two levels (e.g. levels: smoker and non-smoker) vs. more than two levels (e.g. levels: heavy smoker, moderate smoker, occasional smoker, non-smoker).
Be precise. Use the language of the textbook to identify the appropriate test and how you would conduct it. NOTE: Minimum of 150 words for primary post and 50 words for each of three replies to your peers.
In: Math
One state lottery game has contestants select 5 different numbers from 1 to 45. The prize if all numbers are matched is 2 million dollars. The tickets are $2 each.
1) How many different ticket possibilities are there?
2)
One state lottery game has contestants select 5 different numbers from 1 to 45. The prize if all numbers are matched is 2 million dollars. The tickets are $2 each.
1) How many different ticket possibilities are there?
2) If a person purchases one ticket, what is the probability of winning? What is the probability of losing?
3) Occasionally, you will hear of a group of people going in together to purchase a large amount of tickets. Suppose a group of 30 purchases 6,000 tickets.
a) How much would each person have to contribute?
b) What is the probability of the group winning? Losing?
If a person purchases one ticket, what is the probability of winning? What is the probability of losing?
3) Occasionally, you will hear of a group of people going in together to purchase a large amount of tickets. Suppose a group of 30 purchases 6,000 tickets.
a) How much would each person have to contribute?
b) What is the probability of the group winning? Losing?
In: Math
please show all work:
A machine that fills beverage cans is supposed to put 12 ounces of beverage in each can. The standard deviation of the amount in each can is 0.12 ounce. The machine is overhauled with new components, and ten cans are filled to determine whether the standard deviation has changed. Assume the fill amounts to be a random sample from a normal population. 12.14, 12.05, 12.27, 11.89, 12.06, 12.14, 12.05, 12.38, 11.92, 12.14
Perform a hypothesis test to determine whether the standard deviation differs from 0.12 ounce. Use the α = 0.05 level of significance. Evaluate these machines using a Traditional Hypothesis Test.
Hypothesis with claim:
Draw the curve, labeling the CV, TV, and shading the critical region.
CV(s):
TV:
Decision:
In: Math
Work standards specify time, cost, and efficiency norms for the performance of work tasks. They are typically used to monitor job performance. In one distribution center, data were collected to develop work standards for the time to assemble or fill customer orders. The table below contains data for a random sample of 9 orders.
|
Time (mins.) |
Order Size |
|
27 |
36 |
|
15 |
34 |
|
71 |
255 |
|
35 |
103 |
|
8 |
4 |
|
60 |
555 |
|
3 |
6 |
|
10 |
60 |
|
10 |
96 |
In: Math
|
Frequency |
|
|
Rock |
85 |
|
Paper |
110 |
|
Scissors |
105 |
|
Total |
300 |
In: Math
A population of values has a normal distribution with
μ=62.7μ=62.7 and σ=66.2σ=66.2. You intend to draw a random sample
of size n=42n=42.
Find the probability that a single randomly selected value is
greater than 49.4.
P(X > 49.4) =
Find the probability that a sample of size n=42n=42 is randomly
selected with a mean greater than 49.4.
P(M > 49.4) =
Enter your answers as numbers accurate to 4 decimal places. Answers
obtained using exact z-scores or z-scores rounded
to 3 decimal places are accepted.
License
In: Math
Consider the experiment of rolling a six-sided fair die. Let X
denote the number of rolls it takes to obtain the first 5,
Y denote the number of rolls until the first 2, and Z denote
the number of rolls until the first 4. Numerical answers are needed only for parts (a) and
(b). Expressions are sufficient for parts (c), (d), and (e).
a) E[X|Y = 1 or Z = 1]
b) E[X|Y = 1 and Z = 2]
c) E[X|Y = 1 and Z = 3]
d) E[X|Y = 3 and Z = 4]
e) E[X^2 |Y = 3 and Z = 4]
In: Math
Question 1 [35 marks]
|
A foundry that specializes in producing custom blended alloys has received an order for 1 000 kg of an alloy containing at least 5% chromium and not more than 50% iron. Four types of scrap which can be easily acquired can be blended to produce the order. The cost and metal characteristics of the four scrap types are given below: Scrap type |
||||
|
Item |
1 |
2 |
3 |
4 |
|
Chromium |
5% |
4% |
- |
8% |
|
Iron |
40% |
80% |
60% |
32% |
|
Cost per kg |
R6 |
R5 |
R4 |
R7 |
The purchasing manager has formulated the following LP model:
Minimise COST = 6M1 + 5M2 + 4M3 + 7M4
subject to
0,05M1 + 0,04M2 + 0,08M4 ≥ 50 (CHRM)
0,40M1 + 0,80M2 + 0,60M3 + 0,32M4 ≤ 500 (IRON)
M1 + M2 + M3 + M4 = 1000 (MASS)
and all variables ≥ 0,
where Mi = number of kg of scrap type i purchased, i=1,2,3,4.
(a) Solve this model using LINDO or SOLVER.
(b) Write down the foundry's optimal purchasing plan and cost.
Based on your LINDO or SOLVER solution answer the following questions by using only the initial printout of the optimal solution. (This means that you may not change the relevant parameters in the model and do reruns.)
(c) How good a deal would the purchasing manager need to get on scrap type 1 before he would be willing to buy it for this order?
(d) Upon further investigation, the purchasing manager finds that scrap type 2 is now being sold at R5,40 per kg. Will the purchasing plan change? By how much will the cost of purchasing the metals increase?
(e) The customer is willing to raise the ceiling on the iron content in order to negotiate a reduction in the price he pays for the order. How should the purchasing manager react to this?
(f) The customer now specifies that the alloy must contain at least 6% chromium. Can the purchasing manager comply with this new specification? Will the price charged for the order change?
In: Math
The mean of a population is 74 and the standard deviation is 16. The shape of the population is unknown. Determine the probability of each of the following occurring from this population.
a. A random sample of size 32 yielding a sample mean of 76 or more
b. A random sample of size 130 yielding a sample mean of between 72 and 76
c. A random sample of size 220 yielding a sample mean of less than 74.3
In: Math
A population of values has a normal distribution with
μ=81.3μ=81.3 and σ=88.7σ=88.7. You intend to draw a random sample
of size n=168n=168.
Find P80, which is the score separating the
bottom 80% scores from the top 20% scores.
P80 (for single values) =
Find P80, which is the mean separating the
bottom 80% means from the top 20% means.
P80 (for sample means) =
Enter your answers as numbers accurate to 1 decimal place.
************NOTE************ round your answer to ONE digit after
the decimal point! ***********
Answers obtained using exact z-scores or z-scores
rounded to 3 decimal places are accepted.
In: Math
10.7 When people make estimates, they are influenced by anchors to their estimates. A study was conducted in which students were asked to estimate the number of calories in a cheeseburger. One group was asked to do this after thinking about a calorie-laden cheesecake. A second group was asked to do this after thinking about an organic fruit salad. The mean number of calories estimated in a cheeseburger was 780 for the group that thought about the cheesecake and 1,041 for the group that thought about the organic fruit salad. (Data extracted from “Drilling Down, Sizing Up a Cheeseburger's Caloric Heft,” The New York Times, October 4, 2010, p. B2.) Suppose that the study was based on a sample of 20 people who thought about the cheesecake first and 20 people who thought about the organic fruit salad first, and the standard deviation of the number of calories in the cheeseburger was 128 for the people who thought about the cheesecake first and 140 for the people who thought about the organic fruit salad first.
a. State the null and alternative hypotheses if you want to determine whether the mean estimated number of calories in the cheeseburger is lower for the people who thought about the cheesecake first than for the people who thought about the organic fruit salad first.
b. In the context of this study, what is the meaning of the Type I error?
c. In the context of this study, what is the meaning of the Type II error?
d. At the 0.01 level of significance, is there evidence that the mean estimated number of calories in the cheeseburger is lower for the people who thought about the cheesecake first than for the people who thought about the organic fruit salad first?
In: Math
. A manager for an insurance company believes that customers have the following preferences for life insurance products: 40% prefer Whole Life, 10% prefer Universal Life, and 50% prefer Life Annuities. The results of a survey of 310 customers were tabulated. Is it possible to refute the sales manager's claimed proportions of customers who prefer each product using the data?
Product Number Whole 124 Universal 31 Annuities 155
State the null and alternative hypothesis.
What does the null hypothesis indicate about the proportions of fatal accidents during each month?
State the null and alternative hypothesis in terms of the expected proportions for each category.
Find the value of the test statistic. Round your answer to three decimal places.
Find the degrees of freedom associated with the test statistic for this problem.
Find the critical value of the test at the 0.025 level of significance. Round your answer to three decimal places.
Make the decision to reject or fail to reject the null hypothesis at the 0.025 level of significance.
State the conclusion of the hypothesis test at the 0.025 level of significance.
In: Math
Write the null and alternative hypotheses in notation for each of the following statements.
|
3a. [1 point] The μ for scores on the Wechsler Adult Intelligence Test is 100. |
|
3b. [1 point] For a population of 25- to 54-year-old women, the mean amount of television watched each day is 4.4 hours. |
|
3c. [1 point] The mean reaction time of 19-year-old males to a simple stimulus is at least 423.0 milliseconds. |
Given the following information, test whether the population mean is equal to the given value μ0. Provide the following:
|
4a. [3 points] Two-tailed test, μ0=100, σx̄=25, x̄=70, N=86, α=.01 |
|
4b. [3 points] Two-tailed test, μ0=87, Sx̄=2.9, x̄=92, N=37, α=.05 |
In: Math
In: Math
Use for Questions 1-7: Hector will roll two fair, six-sided dice at the same time. Let A = the event that at least one die lands with the number 3 facing up. Let B = the event that the sum of the two dice is less than 5.
1. What is the correct set notation for the event that “at least one die lands with 3 facing up and the sum of the two dice is less than 5”?
2. Calculate the probability that at least one die lands with 3 facing up and the sum of the two dice is less than 5.
3. What is the correct set notation for the event that “at least one die lands with 3 facing up if the sum of the two dice is less than 5”?
4. Calculate the probability that at least one die lands with 3 facing up if the sum of the two dice is less than 5.
5. What is the correct set notation for the event that “the sum of the two dice is not less than 5 if at least one die lands with 3 facing up”?
6. Calculate the probability that the sum of the two dice is not less than 5 if at least one die lands with 3 facing up.
7. Are A and B independent? Explain your reasoning
In: Math