Let X represent the full height of a certain species of tree. Assume that X has a normal probability distribution with u = 110.4 ft and o = 46.4 ft. You intend to measure a random sample of n = 219 trees. What is the mean of the distribution of sample means? What is the standard deviation of the distribution of sample means (i.e., the standard error in estimating the mean)? (Report answer accurate to 2 decimal places.)

Assume that adults have IQ scores that are normally distributed with a mean of 104.5 and a standard deviation 24.7. Find the first quartile Q,. which is the IQ score separating the bottom 25% from the top 75%. (Hint Draw a graph.) The first quartile is (Type an integer or decimal rounded to one decimal place as needed.)

Answer number 3 only pls.

Now suppose that the true mean exposure time is different from 8h/day, yet the sample mean falls in the acceptance region. In this case we would fail to reject H0 when it is false. This type of wrong conclusion is called a A. type II error B. type I error C. no error D. statistically significant

A normal distribution has a Mean of 25 and a S.D. of 10. Find the probability that the deviation from the Mean of an item taken at random will have a negative value.

Provide an original example of some practical case where we can use the normal distribution (e.g., IQ scores follow a normal distribution of probabilities with a mean IQ of 100 and a standard deviation of 15 IQ points.). Assign your numbers for mean 70 and standard deviation 30. Make sure 70 is about four times bigger than 30. Then select any number 90 below or above mean 70, but not too far from 70. Find following two probabilities: 1) P(x < a)2) P(x > a)Use the formula z = (a - μ)/σ to calculate your z-value.  Please refer to the Appendix Table for the Standard Normal Distribution  Hint: To find P(x>a) use formula: P(x>a) = 1 - P(x<a).  Describe how to would find P( 65 < x < 25). Provide an original example to illustrate how to find such probabilities.

A distribution consists of three components with frequencies 45, 40 and 65, having the their mean 2, 2.5, and 2. Show that the mean of the combined distribution is 2.13 approximately.

Let X represent the full height of a certain species of tree. Assume that X has a normal probability distribution with mean 151.4 ft and standard deviation 21.9 ft. You intend to measure a random sample of n = 126 trees. The bell curve below represents the distribution of these sample means. The scale on the horizontal axis is the standard error (standard deviation) of the sampling distribution. Complete the indicated boxes, correct to two decimal places. Submit Question up Ce 23 & 6 8. e y f ge di

Suppose that you have a four-sided die that is equally weighted (i.e. equal chance of any of the four sides landing face up). The four values on the die are [12.5968, 2, -2 and -12.5968] . What is the standard deviation using the conceptual definition? That is, what is the average distance from the data points to the mean?   A. 5.34   B. 4.09   C. 2.58   D. 7.29