A supplier of plastic pellets claims that when the plastic is pressed into wafers of uniform thickness, they will have a mean breaking strength of 165 newtons and a standard deviation of 5 newtons. An engineer at the company randomly selects wafers from 12 batches of pellets.
a)Find the probability that the sample mean is less than 162 newtons.
b)Find the probability that the sample mean is between 164 and 166 newtons inclusive.
c)What did you assume in order to do this analysis? How should you check this assumption?

  1. 👍 0
  2. 👎 0
  3. 👁 186
  1. Z = (sample mean-mean)/SEm (standard error of the mean)

    SEm = SD/√(n-1)

    Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. chemistry

    The density of a certain type of plastic is 0.89 g/cm3. If a sheet of this plastic is 10.0 m long, 1.0 m wide, and 1.0 cm thick, what is its mass?

  2. physics

    A student is testing the kinematic equations for uniformly accelerated motion by measuring the time it takes for light-weight plastic balls to fall to the floor from a height of 3 m in the lab. The student predicts the time to

  3. Algebra 1

    Please help me with this question, Thank You. Mrs. Isabelle is making paper and plastic foam animals for her first-grade class. She is calculating the amount of wasted materials for environmental and financial reasons. Mrs.

  4. physical science

    Fifteen grams of a liquid plastic are frozen in a physical change that increases the volume. What can be known about the plastic after the change? A) It will weigh more than 15 grams. B) It will have an increased density. C) It

  1. MATH

    Plastic plates come in packs of 8, plastic utensils come in packs of 12, and plastic cups come in packs of 20. What are the least numbers of packs you should buy in order to have the same number of plates, utensils, and cups?

  2. physics

    A positively charged glass rod is brought close to a neutral sphere that is supported on a nonconducting plastic stand. Sketch the distribution of charges on the sphere if it is made of: a) Aluminum b) Non-conducting plastic

  3. mah

    the edges of a cubical frame are made from plastic straws. how much longer is the total length of the plastic edges of a cube whose edge is 10cm compared to a cube whose edge is 18cm?

  4. Math

    A factory produces 12000 plastic bottles by using 3 machines 8 hours a day. One machine is out of order now. The owner wants to produce 15000 plastic bottles, How many hours the remaining machines have to work to produce the

  1. chem

    A piece of plastic has a mass of 14.2 grams and volume of 16.8cm cube. What is the mass of 1.00cm cube of this plastic? Thanks for your help.

  2. physics

    A foam plastic of density of 0.58g/cm^3 is to be used as a life jacket.What volume of the plastic must be used if it is to keep 20percent by volume of an 80kg physics student above water in a lake if the average density of the

  3. Social Studies

    How does the use of plastic to produce bicycle helmets affect other plastic-using industries? It decreases the prices offered by other industries. It increases the demand for products of other industries. It increases the capital

  4. statistics

    A manufacturing company produces 10,000 plastic glasses per week. This company supplies plastic glasses to another company, which packages the glasses as part of picnic sets. The second company randomly samples 10 glasses from the

You can view more similar questions or ask a new question.