Random samples of size n were selected from a nonnormal population with the means and variances given here. η 90, μ = 39, σ26 What can be said about the sampling distribution of the sample mean? Since the sample size is --Select- 30, we -Select--v assume that the distribution of x is approximately normal. Find the mean and standard error for this distribution. (Round your standard error to four decimal places.) mean standard error

Let X denote the courtship time for a randomly selected female-male pair of mating scorpion flies (time from the beginning of interaction until mating). Suppose the mean value of X is 120 min and the standard deviation of X is 110 min (suggested by data in the article "Should I Stay or Should I Go? Condition- and Status-Dependent Courtship Decisions in the Scorpion Fly Panorpa Cognate"t). In USE SALT (a) Is it plausible that X is normally distributed? O Yes, courtship time is plausibly normally distributed. Since X must be non-negative, realistically the interval µ ± 30 should be entirely non-negative which is true in this case. O No, courtship time cannot plausibly be normally distributed. Since X must be non-negative, realistically the interval u ± 30 should be entirely non-negative which is not true in this case. O Yes, courtship time is plausibly normally distributed. Since X must be negative, realistically the interval u ± 30 should be entirely negative which is true in this case.…

8. In the UK (United Kingdom) Baby Birth weight can be approximated by a Normal Distribution with N(3.39, 0.55) with numbers being in kg (kilograms) D. Compute P(birth weight > 4 kg) using a normal distribution calculator E. Compute the Z-Score for a 2 kg birth F. Compute P(birth weight < 2 kg) using a normal distribution calculator

We prefer the procedures to the z procedures for inference about a population mean beca (a) can be used only for large samples. (b) z requires that you know the population standard deviation (c) z requires that you can regard your data as an SRS from the population of interest. (d) z requires that your population be Normally distributed. (e) z requires that your observations be independent.