Parametric Test: T-Test & ANOVA

A fisheries researcher is interested in determining whether the average weight of salmon caught in a particular fishing ground is significantly different from 5 kg. She collects a random sample of 16 salmon and calculates the average weight to be 5.3 kg. The standard deviation of the sample is 0.8 kg. The t-statistic calculated from the sample is 2.25. Assuming that the sample is normally distributed and that the population standard deviation is unknown, can we conclude that the average weight of salmon caught in this fishing ground is significantly different from 5 kg at a significance level of α = 0.05?

In a study to compare the mean difference of growth rate of tilapia based on different feeding strategies, researchers collected data on the mean growth rate (in grams per day) of two groups of fish: one group fed a commercial pellet and another group fed a natural diet. The t-statistic calculated from the sample means is 2.45, with 18 degrees of freedom. The null hypothesis is that the true mean growth rate of the two groups is the same. Assuming equal variances, what is the p-value associated with this t-statistic, and what conclusion can be drawn about the difference in growth rate between the two groups?

In a study to identify the mean difference of catch rates of cod based on fishing gear, two researchers compared the average catch rates of cod using otter trawls and gillnets. The data collected from 20 trials with otter trawls and 20 trials with gillnets yielded a t-statistic value of 5.32. The null hypothesis is that the mean catch rates of cod are equal between the two fishing gear types. Based on the given t-statistic value, can you reject the null hypothesis at a significance level of α = 0.01, and what is the conclusion regarding this situation?

In a study to investigate the mean difference of catch rate of yellowfin tuna according to the fishing gear modification, a researcher collected paired data on the mean catch rate (in kg) before and after the modification. The data are as follows: Before modification: 12.5 kg, 10.8 kg, 11.2 kg, 13.1 kg, 12.2 kg, 10.9 kg After modification: 15.6 kg, 14.2 kg, 16.1 kg, 17.3 kg, 15.5 kg, 14.8 kg Using an appropriate test, the researcher obtained a t-statistic value of 2.85. Assuming that the data are normally distributed and the paired differences are independent, at what significance level (α) can the researcher conclude that the fishing gear modification has resulted in a statistically significant difference in the catch rate of yellowfin tuna?

A researcher in fisheries conducted an experiment to study the effect of different fishing gears on the catch rate of fish. The researcher used a paired sample t-test to compare the catch rates of fish caught using two types of fishing nets: Net A and Net B. The mean difference in catch rates was found to be 2.5 kg with a standard error of 0.5 kg. The t-statistic calculated from the data was 4.71. Assuming that the sample size is 20, and the catch rates are normally distributed, can we conclude that the catch rate of fish caught using Net A is significantly higher than that of fish caught using Net B?

A fisheries researcher is interested in comparing the average weight of three different species of fish (A, B, and C) caught in the same fishing grounds. The weights of 10 fish from each species are recorded. This test reveals a F-statistic value of approximately 25.43. What is the statistical test used in this situation? What is the most likely conclusion that can be drawn from these results?

In a study on comparing of the catch rate mean of cod based on different fishing gear types, researchers collected data on the mean catch rate (kg/hour) for each of three fishing gear types: trawl, gillnet, and longline. The data is shown in the table below: Fishing Gear Type Mean Catch Rate (kg/hour) Trawl 2.15 Gillnet 1.43 Longline 0.85 The F-statistic is 123.45. Based on this result, what conclusion can be drawn?

In a study on the effects of two different types of fishing gear (Traditional Gear and Modern Gear) on the catch rate mean of fish in a specific region, two researchers collected data on the average catch rate (in kg/1000 m²) for each gear type over three consecutive years. The researchers want to determine if there is a significant difference in catch rate between the two gear types and if there is a significant difference in catch rate over the three years. They used a two-way ANOVA with the following results: F-statistic for Gear Type= 144.5 F-statistic for Year= 9.2 Using these results, can you conclude that there is a significant difference in catch rate between the two gear types and/or over the three years?

In a study on the growth rate of tilapia in different aquaculture systems, two factors were investigated: type of water filtration system (Type A vs. Type B) and level of feed supplementation (Low, Medium, and High). If the F-statistic for the two-way ANOVA is: F-statistic = 24.5 (Type A vs. Type B) and F-statistic = 36.8 (Low vs. Medium vs. High) Using these results, can you conclude that there is a significant difference in mean of growth rate between different aquaculture systems?

A researcher in aquaculture is studying the growth rate of tilapia based on three factors (water temperature, pH, and feed type). The researcher uses a test with 3 blocks, 3 rows, and 3 columns, and measures the growth rate of 9 tilapia at each treatment combination. The data is analyzed using ANOVA, and the F-statistic values are as follows: F-value for water temperature: 220.12 F-value for pH: 150.85 F-value for feed type: 125.43 If the researcher sets the significance level at α = 0.05, what conclusions can be drawn about this situation?