Concept explainers
Using the Central Limit Theorem. In Exercises 5–10, use this information about the overhead reach distances of adult females: μ = 205.5 cm, σ = 8.6 cm, and overhead reach distances are
8. a. If 1 adult female is randomly selected, find the probability that her overhead reach is greater than 195.0 cm.
b. If 25 adult females are randomly selected, find the probability that they have a mean overhead reach greater than 203.0 cm.
c. Why can the normal distribution be used in part (b), even though the
Want to see the full answer?
Check out a sample textbook solutionChapter 6 Solutions
Essentials of Statistics; MathXL Valuepack Access Card (6-months) (5th Edition)
- VOLTE 13 A researcher in a large university believes that the mean health care expenses of the university differ from the national average of $1570. A sample of 50 people shows an average of $1680 and a standard deviation is $180. Can we say that the mean health care expenses differ from the national average at a= 0.05 ?. (Click the link below to get normal-table values) https://drive.google.com/file/d/1rLJzsws5fYwv usp=sharing (a) Hypothesis: ( If the hypothesis is Ho: u1570 then write 1 in the answer box. If the hypothesis is Ho: u > 1570 and H1: u <1570 then write 2 in the answer box If the hypothesis is Ho: u = 1570 and H1: #1570 then write 3 in the answer box) (b) Critical value = (Example: 3.56) (c) Test Statistic or Calculated value = ( Example : 7.89)arrow_forwardA researcher believes that the so-called “sugar high” is not real. He gathered 30 adolescents and recorded their activity level in the scale of 0 – 100 (0 = not active and 100 = super active). First, he recorded participants’ activity level before they consumed candy. After recording their pre-sugar activity level, the researcher gave out 5 Snickers bars to participants. Then, he recorded their post-sugar activity level. The average difference between post-sugar and pre-sugar activity level is 50 (i.e., the activity levels are higher after sugar than prior to it) with a standard deviation of 10. A). What is the type of test you will use? (z-test, single-sample t-test, paired-samples t-test, or independent samples t-test) and why (what information provided in the problem)B). What are the hypotheses (Be Specific)arrow_forwardD. P(pass/morning) = 0.28 P(pass/afternoon) = 0.53 Conclussion: A student taking the test in the morning has a greater chance of passing it than a student taking it in the afternoon.arrow_forward
- The American Mineralogist (Oct. 2009) published a study of the evolution of uranium minerals in the Earth's crust. Researchers estimate that the trace amount of uranium x in reservoirs follows a uniform distribution ranging between 1 and 3 parts per million. Complete parts a through c. a. Find E(x) and interpret its value. Select the correct answer below and fill in the answer box to complete your choice. (Simplify your answer.) O A. E(X)= This value gives the minimum parts per million of uranium for the collection of all reservoirs on the Earth. O B. E(X)= This value gives the maximum parts per million of uranium for the collection of all reservoirs on the Earth. O C. E(x)= This value gives the mean parts per million of uranium for the collection of all reservoirs on the Earth. O D. E(X)= This value gives the mean parts per million of uranium in each reservoir on the Earth.arrow_forwardP Do Homework Section 64 - Google Chrome mathxl.com/Student/PlayerHomework.aspx?homeworkld%3D587793988&questionld%3D1&flushed%=false&cld%3D635961... Math 1103-4 Spring 2021 Homework: Section 6.4 Save Score: 0 of 1 pt 4 of 4 (0 complete) HW Score: 0%, 0 of 4 pts 6.4.18-T Question Help ▼ A boat capsized and sank in a lake. Based on an assumption of a mean weight of 131 lb, the boat was rated to carry 60 passengers (so the load limit was 7,860 lb). After the boat sank, the assumed mean weight for similar boats was changed from 131 lb to 171 Ib. Complete parts a and b below. a. Assume that a similar boat is loaded with 60 passengers, and assume that the weights of people are normally distributed with a mean of 177.4 lb and a standard deviation of 39.3 lb. Find the probability that the boat is overloaded because the 60 passengers have a mean weight greater than 131 lb. The probability is (Round to four decimal places as needed.) Enter your answer in the answer box and then click Check…arrow_forwardSection 5.1: Normal Distributions X~ N(center, st.dev.) Example 1: Find the specified areas for a standard normal density. The area below z = 0.8 The area above = 1.2 c. The area between z = -1 and z = 2arrow_forward
- Algebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:CengageBig Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt