Toggle navigation Load unfinished survey Resume later Exit and clear survey default Caution: JavaScript execution is disabled in your browser or for this website. You may not be able to answer all questions in this survey. Please, verify your browser parameters. Statistics Knowledge The purpose of this quiz is to help you assess your knowledge of basic statistical concepts. The survey is anonymous. Once you have completed the quiz, the number of correct answers will be shown. There are 16 questions in this survey. Questions Each question has four possible answers, of which only one is correct. If you don't know the correct answer, please select "No answer". Imagine that you collect data on the ages of the people outside a primary school in the morning.The sample distribution would likely be... Choose one of the following answers Unimodal Normal Bimodal Rectangular No answer A colleague mentions that she analysed her data with the t-test and found that the test had a power of 70%. What she meant was that... Choose one of the following answers the probability of observing false positives was 0.7 the probability of observing false negatives was 0.7 the probability of observing false positives was 0.3 the probability of observing false negatives was 0.3 No answer You scored at the 60th percentile in a classroom test. This means that... Choose one of the following answers 60% of your classmates had the same score, or a higher score, than yours Your test score was 60% 60% of your classmates had the same score, or a lower score, than yours Your test score was 40% No answer If all possible samples of size n=30 are selected from a population with mean 80.0 and standard deviation 10.0, and the mean is computed for each sample, then what shape is expected for the distribution of sample means? Choose one of the following answers The sample means tend to form a normal-shaped distribution whether the population is normal or not. The sample means tend to form a normal-shaped distribution only if the population distribution is normal. The sample size of n=30 is too small to predict the shape of the distribution. The mean of each sample will be very close to 80, hence the distribution of means will have little variability. No answer In the Monopoly game the players roll two dice to get the number of steps to move on the board. What is the average step size? Choose one of the following answers 6 6.5 7 7.5 No answer IQ tests are standardised so that the mean IQ score is 100 for a group of peoplewho took the test. You ask 70 people to take the test and find that the average IQ scorewas 112, which is quite different from 100. This discrepancy is due to... Choose one of the following answers statistical error inferential error residual error sampling error No answer You plan to carry out an F-test with a p-value threshold of 0.01 This means that... Choose one of the following answers you expect a false positive result to occur with a probability of 1% you expect the probability of a true positive result to be 1% you expect a false negative result to occur with a probability of 1% you expect a true negative result with 99% probability No answer What happens to the confidence interval if you increase the sample size? Choose one of the following answers Nothing because the confidence interval is independent of the sample size The confidence interval would become broader The confidence interval would become narrower The confidence interval would expand or shrink, depending on the ratio of the mean to the standard deviation No answer You study rat fertility and collect data on the number of offspring in 10 litters. You find that the number of pups in each litter are 8,8,8,9,10,11,12,13,13,14.What is the median litter size? Choose one of the following answers 11 8 10.5 10 No answer The variance is not independent from the mean in the case of... Choose one of the following answers ...the Chi-square distribution ...the Chi-square and the Poisson distribution ...the Poisson distribution ...the Normal distribution No answer You measured the intracellular concentration of ATP in 5 technical replicates and obtained an average concentration of 3.2 mmol/L. According to the statistical package you used, the lower and upper limits of the 95% confidence interval were 2.6 and 3.8 mmol/L. From this result you deduce that... Choose one of the following answers if you repeat the experiment 100 times, then you can expect 95 of the sample average to fall within the range 2.6 - 3.8 mmol/L there is a 95% probability that the true mean will be between 2.6 and 3.8 mmol/L 95 out of 100 population means will fall within the range 2.6 - 3.8 mmol/L the population mean falls within the range 2.6 - 3.8 mmol/L with 5% probability No answer You work on a project to improve the catalytic efficiency of a bacterial enzyme and designed four new sequences containing point mutations. The new sequences are called M1, M2, M3, M4 ("M" for "mutant"). You measure the activities of the wildtype ("WT" group) and each mutant enzyme M1, ... , M4 5 times. How would you identify the most promising mutant? Choose one of the following answers I run ANOVA on the 5 groups WT, M1, ... , M4 and if the F test is significant then I compare M1, ..., M4 to WT using Student's t test. I pick the mutant group whose average mean was the most different from the WT mean, and compare them with Student's t test to confirm. I run ANOVA on the 5 groups WT, M1,...,M4 and if the F test is significant then I compare all groups pairwise using the Tukey HSD test. After that I select the M group that had the lowest p-value when compared to the WT group. I run ANOVA on the 5 groups WT, M1, ... M4 and if the F test is significant then I compare M1, ... M4 to WT using Dunnett's test. No answer You find the third sample quartile at... Choose one of the following answers At the median of the observations whose position is to the right of the median of the overall distribution At the mean of the observations whose position is to the right of the median of the overall distribution At the median of the observations whose position is to the right of the mean of the overall distribution At the median of the observations whose position is to the left of the median of the overall distribution No answer Consider the following figure where the height of the bars correspond to average fluorescence intensities and the error bars represent standard deviations: If you compare the average intensities with the two-group t test, is the intensity difference in the figure significant at the p<0.05 level? Choose one of the following answers Yes, it is significant, because the error bars don't overlap Yes, it is significant, because the "mutant" error range does not contain the average intensity of the "wildtype" and vice versa Significant at the p<0.1 level because the end of the error bars are closer than their length May or may not be significant, depending on the sample size No answer You inject a toxic drug into 20 mice and find that 8 mice died.If you repeat this experiment many times, which probability distribution wouldbest describe the result? Choose one of the following answers A Normal distribution with mean 8.0 and standard deviation 0.4 A Binomial distribution with size parameter 8.0 and probability parameter 0.4 A Normal distribution with mean 20.0 and standard deviation 8.0 A Binomial distribution with size parameter 20 and probability parameter 0.4 No answer Which of the following statements cannot be true after the teacher hasevaluated your answers to this quiz? Choose one of the following answers The majority of the students had scores above the mean The majority of the students had scores above the median The majority of the students had scores above the mode None of the three answers above is true No answer Submit Load unfinished survey Resume later Please confirm you want to clear your response? Exit and clear survey ×
