|
Month |
Nightly customers |
|
0 |
35 |
|
1 |
41 |
|
2 |
46 |
|
3 |
54 |
|
4 |
66 |
|
5 |
84 |
|
6 |
103 |
|
7 |
117 |
|
8 |
141 |
|
9 |
180 |
|
10 |
222 |
|
11 |
275 |
In: Math
For finding p-values, there are two approaches - bootstrap or use a distribution for the test statistic under the null hypothesis (like standard normal, T, Chi-Square, F). Using the distribution approach requires some assumptions (such as normality, or approximate normality, of the population distribution, large sample sizes, etc.) For the following testing scenarios, write down the assumptions that are needed:
a. Testing of equality of proportions between two categorical variables - p1 and p2. Ho: p1 = p2 vs H1: p1 /= p2. Sample size n1 and n2
b. Testing for equality of proportions between three categorical variables using the Chi-Square Goodness of Fit approach Ho: p1 = p2 = p3 vs H1: at least one pair of pi's is not the same. Sample sizes n1, n2, n3. Total sample size n = n1+n2+n3
a. Testing of equality of population means between three populations using the ANOVA table. Ho: mu1 = m2 = mu3 vs H1: not all population means are the same Sample size n1, n2, n3
In: Statistics and Probability
Marge owns three stocks: Apple, Google and Facebook. She expects the price per share of each stock one month from now to be 120, 60, and 60 dollars, respectively. An analysis of the returns to holding these three stocks shows that the monthly standard deviation of the price per share for each stock is 10, 8, and 8 dollars, respectively. This same analysis also concludes the covariance between the price per share of Apple stock and the price per share of Google stock is -36 (dollars squared), between Apple and Facebook it is +24, and between Google and Facebook it is +19. Assume Marge owns 200 shares of Apple, 100 shares of Google, and 50 shares of Facebook.
(a) Compute the expected value of Marge’s portfolio one month from now.
(b) Compute the standard deviation of the value of her portfolio one month from now.
(c) Marge’s sister, Maggie, owns 200 shares of Apple, 50 shares
of Google, and 100 shares of Facebook. Who has the better
portfolio? Explain and show any related work.
In: Statistics and Probability
Question 8. For finding p-values, there are two approaches - bootstrap or use a distribution for the test statistic under the null hypothesis (like standard normal, T, Chi-Square, F). Using the distribution approach requires some assumptions (such as normality, or approximate normality, of the population distribution, large sample sizes, etc.)
For the following testing scenarios, write down the assumptions that are needed
a. Testing of equality of proportions between two categorical variables - p1 and p2.
Ho: p1 = p2 vs H1: p1 /= p2. Sample size n1 and n2
b. Testing for equality of proportions between three categorical variables using the Chi-Square Goodness of Fit approach
Ho: p1 = p2 = p3 vs H1: at least one pair of pi's is not the same. Sample sizes n1, n2, n3. Total sample size n = n1+n2+n3
a. Testing of equality of population means between three populations using the ANOVA table.
Ho: mu1 = m2 = mu3 vs H1: not all population means are the same Sample size n1, n2, n3
In: Statistics and Probability
Time spent using e-mail per session is normally distributed, with mu equals 8 minutes and sigma equals 2 minutes. Complete parts (a) through (d).
a. If you select a random sample of 25 sessions, what is the probability that the sample mean is between 7.8 and 8.2 minutes?
=0.3830 (Round to three decimal places as needed.)
b. If you select a random sample of 25 sessions, what is the probability that the sample mean is between 7.5 and 8 minutes?
= 0.3944 (Round to three decimal places as needed.)
c. If you select a random sample of 200 sessions, what is the probability that the sample mean is between 7.8 and 8.2 minutes?
d. Explain the difference in the results of (a) and (c). Choose the correct answer below. The sample size in (c) is greater than the sample size in (a), so the standard error of the mean (or the standard deviation of the sampling distribution) in (c) is ......... than in (a). In general, as the standard deviation decreases, values become ........ concentrated around the mean. Therefore, the probability of a region that includes the mean will always ........ when the sample size increases.
In: Statistics and Probability
Python program
A number game machine consists of three rotating disks labelled with the numbers 0 to 9 (inclusive). If certain combinations of numbers appear when the disks stop moving, the player wins the game.
The player wins if
otherwise the player loses.
Write a Python program to simulate this number game by randomly generating 3 integer values between 0 and 9 (inclusive), and printing whether the player has won or lost the game.
To randomly generate a number between and including 0 and 9, use the randintmethod from random library module. For example, x = random.randint(1,100)will automatically generate a random integer between 1 and 100 (inclusive) and store it in x.
Sample output 1:
Random numbers: 2 3 5 You lose.
Sample output 2:
Random numbers: 7 7 0 You win!
In: Computer Science
Drosophila has three linked autosomal genes that determine different traits. These genes are black (b), vestigial (vg), and singed(sn). Each of the three genes has two alleles: a dominant wild type allele, indicated by a "+" (plus) and a recessive mutant allele indicated by a "-" (minus). (These mutant alleles cause dark black spots, short "vestigial" wings, and bent "singed" hairs, respectively, when homozygous). A testcross is conducted between females that all have the same genotype and are triple heterozygotes for the three genes, and males that are all homozygous mutant for all three genes. Here are the numbers of progeny from the testcross, of each of the different possible phenotypes:
Progeny
Group
Phenotype Number
1 b+ vg - sn- 638
2 b+ vg + sn- 2768
3 b- vg + sn+ 621
4 b+ vg + sn+ 9
5 b+ vg- sn+ 126
6 b- vg - sn- 7
7 b- vg + sn- 132
8 b- vg - sn+ 2699
Total # progeny = 7000
In the answer box below, give your answers to parts A and B.
A. From the data above, determine the genotype of the triple heterozygous females used in the testcross; in your genotype, be sure to include the proper order of the genes on the chromosomes. Indicate the genotype with a slash between the two homologous chromosomes (8 points)
(Example of format for an answer: a+ b- c- / a- b+
c+
but use b, vg and sn instead of a, b and c, and put them in the
correct order with the correct + and - alleles on the same
homologue)
B. Type in three equations, numbered 1, 2, and 3. each with the
proper numbers for calculating the genetic distances between the
genes indicated (You do not need to complete the
calculation.) (6 points)
1. black (b) and vestigial (vg)
2. vestigial (vg) and singed (sn)
3. black (b) and singed (sn)
Format for each answer: For example, if to determine the
distance for #1, between black and vestigial, you think you should
add the progeny in group 4 and the progeny in group 5 and divide by
the total number of progeny, type this as your answer:
1. 9+126/7000 (Of course,
this is not the correct answer for #1!)
In: Biology
We wish to compare the PsyCap scores of our class to a predetermined standard set by a study conducted in 2014. The population mean for this standard is 121. 58 with a standard deviation of 11.29.
Utilizing the steps of hypothesis testing, determine if the scores of our class are equal to those of the standard using a 95% confidence level.
| 28 | 33 | 32 | 31 | 124 | |
| 30 | 22 | 33 | 22 | 107 | |
| 32 | 29 | 31 | 27 | 119 | |
| 20 | 24 | 29 | 30 | 103 | |
| 24 | 23 | 27 | 32 | 106 | |
| 32 | 33 | 33 | 29 | 127 | |
| 29 | 22 | 27 | 24 | 102 | |
| 36 | 30 | 32 | 29 | 127 | |
| 23 | 17 | 21 | 21 | 82 | |
| 36 | 22 | 36 | 24 | 118 | |
| 24 | 29 | 26 | 25 | 104 | |
| 21 | 26 | 29 | 19 | 95 | |
| 26 | 21 | 24 | 24 | 95 | |
| 27 | 28 | 31 | 27 | 113 | |
Answer
Step 1
Our Hypothesis
Ho: Ho = μ = 121.58 (equal to(null))
Ha: μ ≠ 121.58 (not equal to (alternative))
Step 2
Specify the significance level a(alpha)
a = 0.05
Step 3 (also step 5)
Select the test statistic (two tailed test, this means two rejecting regions)
(103.76-121.58)/ 11.29/ square root of 17 = -6.507
0.95
0.025 0.025
-1.96 1.96
Step 4
The rule is to decide whether the z equals that of Ho, if it is less or more we reject and favor the alternative Ha
Step 5
(103.76-121.58)/ 11.29/ square root of 17 = -6.507
0.95
0.025 0.025
-1.96 1.96
Step 6 Decide whether to reject Ho
Because the result was -6.507, we choose to reject Ho
Step 7
We conclude that scores are below 2014’s data, meaning it is not equal.
In: Statistics and Probability
A vehicle quality survey asked new owners a variety of questions about their recently purchased automobile. One question asked for the owner’s rating of the vehicle using categorical responses of average, outstanding, and exceptional. Another question asked for the owner’s education level with the categorical responses some high school, high school graduate, some college, and college graduate. The Excel Online file below contains the sample data for 500 owners who had recently purchased an automobile. Construct a spreadsheet to answer the following questions.
Observed Frequency Table
| Education | |||||
| Quality Rating | Some HS | HSGrad | SomeCollege | CollegeGrad | Total |
| Average | 23 | 21 | 31 | 60 | 135 |
| Outstanding | 52 | 50 | 45 | 88 | 235 |
| Exceptional | 25 | 29 | 24 | 52 | 130 |
| Total | 100 | 100 | 100 | 200 | 500 |
Expected Frequency Table
| Education | |||||
| Quality Rating | SomeHS | HSGrad | SomeCollege | CollegeGrade | Total |
| Average | 27 | 27 | 27 | 81 | |
| Outstanding | 47 | 47 | 94 | ||
| Exceptional | 26 | 26 | 52 | ||
| Total | 100 | 100 | 27 | 0 | 227 |
a. Use a .05 level of significance and a test of independence to determine if a new owner's vehicle quality rating is independent of the owner's education.
Compute the value of the test statistic (to 2 decimals).
???????
The p-value is ????? (to 4 decimals).
What is your conclusion?
Cannot conclude that the quality rating is not independent of the education of the owner.
b. Use the overall percentage of average, outstanding, and exceptional ratings to comment upon how new owners rate the quality of their recently purchased automobiles.
Average: 27% (to whole number)
Outstanding: 47% (to whole number)
Exceptional: 26% (to whole number)
New owners appear to be satisfied with the recent purchase of their automobile. 73% (to whole number) of owners rated their automobile as Outstanding or Exceptional.
In: Statistics and Probability
ASAP due tonight!
|
Wally’s Widget Company (WWC) incorporated near the end of 2011. Operations began in January of 2012. WWC prepares adjusting entries and financial statements at the end of each month. Balances in the accounts at the end of January are as follows: |
| Cash | $ | 19,220 | Unearned Revenue (40 units) | $ | 4,550 | ||
| Accounts Receivable | $ | 10,250 | Accounts Payable (Jan Rent) | $ | 1,700 | ||
| Allowance for Doubtful Accounts | $ | (1,100) | Notes Payable | $ | 15,500 | ||
| Inventory (45 units) | $ | 3,600 | Contributed Capital | $ | 5,400 | ||
| Retained Earnings – Feb 1, 2012 | $ | 4,820 | |||||
| • | WWC establishes a policy that it will sell inventory at $175 per unit. |
| • | In January, WWC received a $4,550 advance for 40 units, as reflected in Unearned Revenue. |
| • | WWC’s February 1 inventory balance consisted of 45 units at a total cost of $3,600. |
| • | WWC’s note payable accrues interest at a 12% annual rate. |
| • | WWC will use the FIFO inventory method and record COGS on a perpetual basis. |
| February Transactions | |
| 02/01 |
Included in WWC’s February 1 Accounts Receivable balance is a $1,900 account due from Kit Kat, a WWC customer. Kit Kat is having cash flow problems and cannot pay its balance at this time. WWC arranges with Kit Kat to convert the $1,900 balance to a note, and Kit Kat signs a 6-month note, at 12% annual interest. The principal and all interest will be due and payable to WWC on August 1, 2012. |
| 02/02 |
WWC paid a $700 insurance premium covering the month of February. The amount paid is recorded directly as an expense. |
| 02/05 |
An additional 150 units of inventory are purchased on account by WWC for $9,000 – terms 2/15, n30. |
| 02/05 |
WWC paid Federal Express $600 to have the 150 units of inventory delivered overnight. Delivery occurred on 02/06. |
| 02/10 |
Sales of 120 units of inventory occurred during the period of 02/07 – 02/10. The sales terms are 2/10, net 30. |
| 02/15 |
The 40 units that were paid for in advance and recorded in January are delivered to the customer. |
| 02/15 |
25 units of the inventory that had been sold on 2/10 are returned to WWC. The units are not damaged and can be resold. Therefore, they are returned to inventory. Assume the units returned are from the 2/05 purchase. |
| 02/16 | WWC pays the first 2 weeks wages to the employees. The total paid is $2,600. |
| 02/17 |
Paid in full the amount owed for the 2/05 purchase of inventory. WWC records purchase discounts in the current period rather than as a reduction of inventory costs. |
| 02/18 | Wrote off a customer’s account in the amount of $1,200. |
| 02/19 |
$3,400 of rent for January and February was paid. Because all of the rent will soon expire, the February portion of the payment is charged directly to expense. |
| 02/19 |
Collected $8,400 of customers’ Accounts Receivable. Of the $8,400, the discount was taken by customers on $5,500 of account balances; therefore WWC received less than $8,400. |
| 02/26 |
WWC recovered $440 cash from the customer whose account had previously been written off (see 02/18). |
| 02/27 |
A $700 utility bill for February arrived. It is due on March 15 and will be paid then. |
| 02/28 | WWC declared and paid a $400 cash dividend. |
| Adjusting Entries: |
| 02/29 |
Record the $2,600 employee salary that is owed but will be paid March 1. |
| 02/29 |
WWC decides to use the aging method to estimate uncollectible accounts. WWC determines 8% of the ending balance is the appropriate end of February estimate of uncollectible accounts. |
| 02/29 | Record February interest expense accrued on the note payable. |
| 02/29 |
Record one month’s interest earned Kit Kat’s note (see 02/01). I need help making the journal entries! Help ASAP thank you! |
In: Accounting