longevity (days) Oneway Analysis of longevity (days) By Status 90 80 70 60 50 40 30 20 10 active Status inactive
Q: Lightbulbs of a certain type are advertised as having an average lifetime of 750 hours. The price of…
A: Solution Given the test is a left tailed test So the alternative hypothesis is left tailed.
Q: A researcher randomly selected a sample of n = 500 individuals from a population with µ = 120 and…
A: The question is about hypothesis testing.Given :Randomly selected no. of individuals ( n ) = 500Mean…
Q: A study was performed to determine whether men and women differ in repeatability in assembling…
A: Given: n1=28n2=25s1=1.98s2=2.31α=0.02
Q: the body temperature of two species of geckos were measured. the n1 = 10 geckos from species A had a…
A: Consider, the pooled variance, spooled2=(n1-1)s12+(n2-1)s22n1+n2-2…
Q: Sony would like to test the hypothesis that the average age of a PlayStation user is different from…
A: Step 1: It is considered that μ1 and μ2 define the population average age of PlayStation users…
Q: population variance is 3.68. Would this sample be considered significantly different from the…
A:
Q: An engineer is comparing voltages for two types of batteries (K and Q) using a sample of 71 type K…
A:
Q: The recommended daily dietary allowance for zinc among males older than age 50 years is 15 mg/day.…
A: Given that, Mean, x bar= 12.2 Sample size, n=115 And standard deviation, sigma= 6.93 Here we've to…
Q: The senior vice president for marketing at Kean Hotel believes that the company’s recentadvertising…
A: Given data and calculation for mean and standard deviation is shown below- Calculate mean using…
Q: A researcher obtains a sample of n= 25 adults who are between the ages of 65 and 75. The researcher…
A: Hello. Since your question has multiple sub-parts, we will solve first five sub-parts for you. If…
Q: A psychologist reports that the average length of R.E.M. sleep in his test subjects was 10 minutes.…
A: Hypothesis Testing: Hypothesis is a procedure by which we can tests an assumption regarding a…
Q: If were regressing with an endogenous variable used as an independent variable, and employing the…
A: In the context of regression analysis with an endogenous variable used as an independent variable…
Q: From the data given what would be the correct p value? (the one tail or the two tail?) 2. Find the…
A: Here we have to determine , determine if the true average number of minutes per charge for NiMH…
Q: Are Republicans more likely than Democrats to display the American flag in front of their residence…
A: Given Information: Republicans: Sample size (n1) = 679 Out of which x1 = 448 displayed the flag on…
Q: The Cincinnati Enquirer reported that, in the United States, 60% of adults and 82% of youths ages 12…
A: Let X be a random variable following normal distribution with mean μ and variance σ2, i.e.,…
Q: A researcher used a sample of n =16 adults between the ages of 40 and 45. For each person, the…
A: Given information, A researcher used a sample of n =16 adults between the ages of 40 and 45. For…
Q: Q tests are made to have an average score of 100. Psychologists revise the test every few years in…
A: Given that IQ tests are made to have an average score of 100 (μ) = 100 Bell shaped distribution (…
Q: Data from the Motor Vehicle Department indicate that 80% of all licensed drivers are older than age…
A: Given: sample size, n = 50 number of drivers older than 25 years = 33 Sample proportion, p^ = 33/50…
Q: Lightbulbs of a certain type are advertised as having an average lifetime of 750 hours. The price of…
A: Decision rule: If the P-value of the test is less than the level of significance, reject H0.…
Q: Recent results suggest that children with ADHD tend to watch more TV than children who are not…
A: Given Information- Sample size, n = 36 Sample mean, x-bar = 4.9 hours Population mean, μ = 4.1…
Q: Tardigrades, or water bears, are a type of micro-animal famous for their resilience. In examining…
A: Given that Sample size n =28 Sample mean=836 Standard deviation =60
Q: Recent results suggest that children with ADHD tend to watch more TV than children who are not…
A:
Q: A researcher administers a new treatment to a sample of participants selected from a population with…
A: According to the provided information, a sample of participants selected from a population with µ =…
Q: The lowest level of significance to reject the null hypothesis of no linear association between…
A: Rejection rule: Reject the null hypothesis if the p-value is less than the level of significance.
Q: An engineer is comparing voltages for two types of batteries (K and Q) using a sample of 35 type K…
A: There are two independent samples which are type K batteries and type Q batteries. We have to test…
Q: Probability Scores 0.5 1 0.05 3 0.3 8 0.1 9. 0.05 12 Find the variance of the above random variable…
A: We have given that the random variable X that is Scores and their probability in tabulated form.
Q: A study of parental empathy for sensitivity cues and baby temperament (higher scores mean more…
A:
Q: Lightbulbs of a certain type are advertised as having an average lifetime of 750 hours. The price of…
A:
Q: A state agency requires a minimum of 5 parts per million (ppm) of dissolved oxygen in order for the…
A: (a) That is, there is no evidence to conclude that there is sufficient evidence to indicate that…
Q: If a researcher obtains a sample mean of M= 54, from a population with u = 46. With a given alpha,…
A: Given, If a researcher obtains a sample mean of M= 54, from a population with u = 46.
Longevity, in days, was measured in two unrelated samples of D.
melanogaster flies. Researchers hypothesized that the energetic
demands of sexual activity would cause those flies to have
reduced longevity. Perform all 7 steps of the appropriate hypothesis test to
determine if there is convincing evidence at α = 0.05 that sexually
active D. melanogaster tend to have shorter lifespans than their
sexually inactive counterparts.
Sample |
Sample SD | n | |
active | 38.9 | 12.0 | 25 |
Inactive | 62.5 | 14.1 | 24 |
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- 8.35 When Calories Are Consumed Researchers hypothesized that the increased weight gain seen in mice with light at night might be caused by when the mice are eating. (As we have seen in the previ- ous exercises, it is not caused by changes in amount of food consumed or activity level.) Perhaps mice with light at night eat a greater percentage of their food during the day, when they normally should be sleeping. Conditions for ANOVA are met and com- puter output for the percentage of food consumed during the day for each of the three light conditions is shown. Level e DM LD LL N 10 Light Error Total 8 9 Mean 55.516 36.028 76.573 One-way ANOVA: DayPct versus Light Source DF MS 2 24 26 St Dev 10.881 8.403 9.646 SS 6987.0 2304.3 9291.2 3493.5 96.0 F 36.39 P 0.000 (a) For mice in this sample on a standard light/dark cycle, what is the average percent of food con- sumed during the day? What percent is con- sumed at night? What about mice that had dim light at night? (b) Is there evidence that…suppose that 43% of people who enter a store will make a purchase. Random samples of people who walk into a particular store is studied, and the proportion of those who made a purchase is found for each sample. Assume that all the samples were the same size. If 29.46% of all sample proportions are less than 0.3274. What was the z-score for 0.3274? What is σp′?Is there a difference in pulse rates between male and female adults? In an experiment on a large group of first year university students, each student measured their pulse rates (at rest) on three different days. The average of the three pulse rates was then recorded for each student. Appropriate Excel output (using α = 0.01) is provided. a) Quantify the evidence for a significant difference in the mean pulse rate for males and females. Support your answer with an appropriate hypothesis test that draws on the Excel output provided at α = 0.01. State your conclusions clearly. b) Would the conclusions for this test be applicable to the general populations of male and females? Comment on any bias in the results that may have been introduced by using these samples. c) Calculate a 99% confidence interval for the mean difference in pulse rates for males and females based on this data
- An electrical engineer wishes to compare the mean lifetimes of two types of transistors in an application involving high-temperature performance. A sample of 60 transistors of type A were tested and were found to have a mean lifetime of 1827 hours and a standard deviation of 174 hours. A sample of 180 transistors of type B were tested and were found to have a mean lifetime of 1658 hours and a standard deviation of 231 hours. Let ux represent the population mean for transistors of type A and µy represent the population mean for transistors of type B. Find a 95% confidence interval for the difference uy – µy . Round the answers to three decimal places. The 95% confidence interval isA major credit card company is investigating whether the distribution of the number of credit cards used by its customers has changed from last year to this year. Customers are classified as using 1 card, 2 cards, or more than 2 cards. The company conducts a chi-square goodness-of-fit test to investigate whether there is a change in the distribution of number of cards used from last year to this year. The value of the chi-square test statistic was χ2=7.82χ2=7.82 with a corresponding pp-value of 0.02. Assuming the conditions for inference were met, which of the following is the correct interpretation of this pp-value?A researcher used a sample of n =16 adults between the ages of 40 and 45. For each person, the researcher recorded the difference between the ratings obtained while smiling and the rating obtained while frowning. On average the cartoons were rated as funnier when the participants were smiling, with an average difference of MD = 1.6, with SS = 135. Are the cartoons rated as significantly funnier when the participants are smiling ? Use a one-tailed test with α = .05. a. The null hypothesis in words is: b. The alternative hypothesis in symbols is: c. The critical t-value is d. The t-statistic is e. Your decision is f. Compute r2 to measure the size of the treatment effect. r2 is g. Report the results in APA. Include r2 as a measure of the effect size.
- The paper "The Curious Promiscuity of Queen Honey Bees (Apis mellifera): Evolutionary and Behavioral Mechanisms"† describes a study of the mating behavior of queen honeybees. The following quote is from the paper. "Queens flew for an average of 24.2 ± 9.21 minutes on their mating flights, which is consistent with previous findings. On those flights, queens effectively mated with 4.6 ± 3.47 males (mean ± SD)." The intervals reported in the quote from the paper were based on data from the mating flights of n = 30 queen honeybees. One of the two intervals reported was identified as a 95% confidence interval for a population mean. Which interval is this? Justify your choice. a.The interval, 24.2 ± 9.21 minutes, is the 95% confidence interval because the statement is about the average flight time. b.The interval, 24.2 ± 9.21 minutes, is the 95% confidence interval because the statement is about the flight time.carefully watched over a number of feedings. If it used its right paw more than half the time to activate the tube, it was defined to be “right-pawed." Observations of this sort showed that 67% of mice belonging to strain A/J are right-pawed. A similar protocol was followed on a sam- ple of thirty-five mice belonging to strain A/HeJ. Of those thirty-five, a total of eighteen were eventually classified as right-pawed. Test whether the proportion of right-pawed mice found in the A/HeJ sample was significantly differ- ent from what was known about the A/J strain. Use a two- sided alternative and let 0.05 be the probability associated with the critical region.Are juvenile defendants who are released pending adjudication processed more slowly than those who are detained? The JDCC data set records whether a juvenile was released and the number of months it took for that juvenile’s case to reach a disposition. The sample will be narrowed to black female youth. Released juveniles (Sample 1) had a mean of 4.30 months to disposition (s = 3.86, N = 123) and detained juveniles (Sample 2) had a mean of 3.57 (s = 4.20, N = 64). Using an alpha level of .01, test the hypothesis that released juveniles’ mean time-to-adjudication is significantly greater than detained juveniles’ mean. Assume equal population variances. Use all five steps.
- Denny studied factors affecting cardiovascular reactivity to a postural change in a sample of healthy men and women. Change in systolic blood pressure (SBP) from supine to standing position was used as the measure of cardiac reactivity in a sample of 842 adults. Supine measurement of blood pressure was taken after participants had lain on an examination table for 15 minutes. Blood pressure was determined every 30 seconds using a Dinamap device for 2 minutes, and the measurements were averaged. Participants then stood up immediately, and additional measurements were made for another 2 minutes. Below is a table describing the characteristics of Denny’s sample: Which measures of dispersion, if any, are presented in this table (Ranges, SDs)? If age is normally distributed, approximately what percent of the sample would be younger than 50? If BMI is normally distributed, approximately what percent of the sample would have a BMI higher than 33.1?For the general population, the average fatigue level is μ = 50. A researcher is testing the hypothesis that engaging a meditation exercise reduces employee fatigue. A sample of n = 30 participants is obtained, and each participant engaged in a meditation exercise for 20 minutes at work each workday for a month. This sample’s average fatigue level was M = 46 with a sample variance of 100 after the month. Please write out the four steps for this hypothesis test assuming an alpha level of .05. Step 1: State your hypotheses Step 2: Find your critical regions in a distribution Step 3: Data Analysis Step 4: Making a decision