Xbar distribution of sample means

Assignment Help Basic Statistics
Reference no: EM1319634

1. General: Suppose that x has a distribution with µ = 72 and σ = 8.

(a) If random sample of size n = 16 are selected, can we say anything about the xbar distribution of sample means?

(b) If the original x distribution is normal, can we say anything about the xbar distribution of random samples of size 16? Find P (68 ≤ x ≤73).

2. Vital Statistics: Heights of men The heights of 18 year old men are approximately normally distributed, with mean 68 inches and standard deviation 3 inches.

(a) What is the probability that an 18 year old man selected at random is between 67 and 69 inches tall?

(b)If random sampling of nine 18 year old men is selected, what is the probability that the mean height xbar is between 67 and 69 inches?

(c) Compare your answers for parts (a) and (b). Is the probability in part (b) much higher? Why would you expect this?

Reference no: EM1319634

Questions Cloud

Probability based on bivariate normal distribution : Suppose that a model for the joint distribution of these rvs is a bivariate normal distribution.
Implementing the program for carrying out the calculation : Write down a program that has a function named presentValue which carry out this calculation. The function must accept the future value, annual interest rate, and number of years as arguments.
Evaluating probability of getting opposed in survey : Suppose that 50% of all people are opposed, evaluate probability of getting at least 89% opposed in survey of 1012 randomly selected people.
Objective questions based on regression : Objective questions based on regression
Xbar distribution of sample means : If random sample of size n = 16 are selected, can we say anything about the xbar distribution of sample means?
Standardized test is randomly selected for probability : A student with a 3.5 to 4 grade point average who took standardized test is randomly selected. Determine the probability that students test score is less than 36.
Objective questions on regression : Objective questions on regression
Probability distribution of x : What can we say about the probability distribution of x? Is it approximately normal? What are the mean and standard deviation?
Describing z-score within standard deviations of mean : It is not unusual for a battery to have life span that is more than 2470 hours as the z-score is  within 2 standard deviations of mean.

Reviews

Write a Review

Basic Statistics Questions & Answers

  Determining standard deductions with standard deviation

Survey of 16 tax returns reports families with incomes between $75,000 and 100,000 have on average $8,562 in Standard Deductions with the standard deviation of $1,800.

  Pearsons correlation coefficient

Does the weight of a vehicle affect the gas mileage? The following random sample was collected where  x  = weight of a vehicle in hundreds of pounds and  y  = miles per gallon.

  What was the mean ranking for the females in this class

The chance both flights are full is 0.6. Are the two flights being full independent events and What was the mean ranking for the females in this class

  Create a cumulative percentage distribution

Form the cumulative percentage distribution and plan a cumulative percentage polygon.

  Probability based on relative-frequency

Find out the expected winnings for a person who buys one ticket.

  Explain spss partial output

An experiment was performed to investigate lifetime of a component exposed to high heat. Three different oven types were used at either 550°F or 600°F.

  Difference in the mean times

Below are the sample times in minutes. At the .05 significance level, can we conclude that there is a difference in their mean times?

  Time plot of the values of variable

Consider the following time plot of the values of variable Y for each month of a 60-month period.  This plot displays

  Determining p-value for hypothesis test

Test this conjecture with formal hypothesis test, by using a 5% significance level. Find out the p-value for hypothesis test.

  Describe the data which show a seasonal effect

Describe the given data show a seasonal effect using moving average method. Describe the data which show a seasonal effect.

  Evaluate the sum of the ranks for additive

One characteristic of billiard balls is their elasticity - the bounce they get when striking one another. A manufacturer of billiard balls is testing three additives to the basic plastic.

  How to test the difference in two proportions

A test was conducted to find out whether gender of a spokesperson affected the likelihood that consumers would prefer a new product.  A survey of consumers at trade show employing a female spokesperson determined that 70 out of 150 customers prefe..

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd