Reference no: EM13923598
Q1. A prison psychologist recorded the number of rule infractions for 15 prison inmates over a six-month period to be 5, 4, 2, 4, 3, 5, 2, 0, 4, 4, 5, 5, 3, 4, and 3.
a. Make a frequency table.
b. Make a histogram based on the frequency table.
c. Describe in words the shape of the histogram.
Q2. Identify and solve this problem by hand.
The head of public safety notices that the average driving speed at a particular intersection averages μ = 35 mph with a standard deviation of σ = 7.5 mph. After a school speed limit sign of 20 mph is placed at the intersection, the first 40 cars travel past at an average speed of 32 mph. Using the .01 significance level, was there a significant change in driving speed?
which under the null hypothesis follows a standard normal distribution.
Critical region: Reject H0 iff the absolute value of the test statistic is greater than 2.57583 ( point on a standard normal distribution above which 0.5% of the distribution lies)
Conclusion: Null hypothesis is accepted at 1% level of significance.
a. Sketch the distributions involved.
b. Figure the confidence limits for the 99% confidence interval.
Q3. A social psychologist gave a questionnaire about concern for farm workers to seven participants before and after they attended a film about union organization of farm workers. The results are shown below with high scores meaning high concern. Using the .05 significance level, do these results support the hypothesis that the film affected concern for the lives of farm workers?
Scores on the Concern Measure
Participant Before After
H0:
H1:
Mean before=10.714
Mean after =11
Standard deviation before=3.4017
Standard deviation after=5.774
Z==0.0825
Z-tabulated for two sided=1.96
Since 1.96>0.0825 we accept null hypothesis and conclude that film does not affect concern for the life of farm workers
b. Figure the effect size and find the approximate power of this study.
Q4. A team of cognitive psychologists studying the effects of sleep deprivation on short-term memory decay had eight participants stay in a sleep lab for two days. Four participants were randomly assigned to a condition in which they were not permitted to sleep during that period, while the other four participants were allowed to sleep when they wanted to. At the end of the two days, the participants completed a short-term memory task that yielded the results in the table that follows. Using the .05 significance level, did sleep deprivation reduce short-term memory?
Mean Number of Letters Remembered
Sleep Deprived Normal Sleep
7 9
8 8
7 11
9 7
a. Create the appropriate graph for this problem.
b. Use the five steps of hypothesis testing.
c. Figure the effect size.
d. From the hypothesis testing results, we conclude that there was no effect of sleep deprivation on short memory. There was no significant difference on the effects of the two, both the normal sleep and the ones who were deprived of sleep. The mean number of letters remembered for those who were deprived of sleep was 7.75 while as the mean for those with normal sleep was 8.75.
|
Critical value approach to test the hypothesis
: Discover Card would like to set α = 0.05. Define Population 1 as Dallas and Population 2 as Houston and use the critical value approach to test this hypothesis.
|
|
What is the opportunity cost of cash option over first year
: The new car costs $19,999. Two options; 1) down payment of 20% and finance the balance with no interest and payments for the first few months, 2) or get a rebate of $1,000 if pays cash. The financing alternative would require to pay $460 a month for ..
|
|
Optimal decision rules for katrina candies
: From the scenario for Katrinas Candies, suggest one (1) method in which Herb could use a cost benefit analysis to argue for or against an expansion. Create three (3) optimal decision rules for Katrina's Candies (e.g., whether to hire more staff or..
|
|
Incurable muscle-wasting disease
: Muscular dystrophy is an incurable muscle-wasting disease. If a woman has a child with muscular dystrophy the probability is 2/3 that she is a carrier and 1/3 that she is not a carrier. There is a screening test called the CK test that is positive..
|
|
Make a histogram based on the frequency table
: Q1. A prison psychologist recorded the number of rule infractions for 15 prison inmates over a six-month period to be 5, 4, 2, 4, 3, 5, 2, 0, 4, 4, 5, 5, 3, 4, and 3. a. Make a frequency table. b. Make a histogram based on the frequency table.
|
|
Understanding of internal control
: Smith, a certified public accounting firm, was engaged to audit the financial statements of the Sky-is-the-Limit company. The company has its own IT installation. While obtaining an understanding of internal control, Smith found that Sky-is-the-Li..
|
|
What is optimal number of futures contract that must be sold
: Assuming the bond speculator wants to hedge her net bond position, what is the optimal number of futures contracts that must be bought or sold?
|
|
Ancient sculpture of a human form
: When you look at ancient art, particularly ancient sculpture of a human form, you see progression in how the body is represented. For this assignment, find 3 different sculptures of the human form, all from the ancient period (created between 30,0..
|
|
Standard deviation of his waiting time
: What is the standard deviation of his waiting time? What is the probability that the rst order takes longer than 12 minutes?
|