# Question: Entomologists are continually searching for new biological agents to control

Entomologists are continually searching for new biological agents to control the water hyacinth, one of the world’s worst aquatic weeds. An insect that naturally feeds on the water hyacinth is the delphacid. Female delphacids lay anywhere from one to four eggs onto a water hyacinth blade. The Annals of the Entomological Society of America (Jan. 2005) published a study of the life cycle of a South American delphacid species. The following table gives the percentages of water hyacinth blades that have one, two, three, and four delphacid eggs:

a. One of the water hyacinth blades in the study is randomly selected, and x, the number of delphacid eggs on the blade, is observed. Give the probability distribution of x.

b. What is the probability that the blade has at least three delphacid eggs?

a. One of the water hyacinth blades in the study is randomly selected, and x, the number of delphacid eggs on the blade, is observed. Give the probability distribution of x.

b. What is the probability that the blade has at least three delphacid eggs?

## Answer to relevant Questions

According to Wired (June 2008), 35% of the world’s solar energy cells are manufactured in China. Consider a random sample of 5 solar energy cells, and let x represent the number in the sample that are manufactured in ...Consider the probability distribution shown here: a. Calculate μ, σ2, and σ. b. Graph p(x). Locate μ, μ – 2σ, and μ + 2σ on the graph. c. What is the probability that x will fall into the interval μ ± 2σ? Suppose x is a binomial random variable with n = 3 and p = .3. a. Calculate the value of p(x), x = 0, 1, 2, 3, using the formula for a binomial probability distribution. b. Using your answers to part a, give the ...The United States Department of Agriculture (USDA) reports that, under its standard inspection system, one in every 100 slaughtered chickens passes inspection with fecal contamination (Tampa Tribune, Mar. 31, 2000). In ...The Journal of Economic Psychology (Sept. 2008) published the results of a high-stakes experiment where subjects were asked how much they would pay for insuring a valuable painting. The painting was threatened by fire and ...Post your question