Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Lecture Slides on Introduction to Statistical Analysis - Homework 10 | STAT 245, Assignments of Data Analysis & Statistical Methods

Material Type: Assignment; Class: Introduction to Statistical Analysis; Subject: Statistics; University: Ohio State University - Main Campus; Term: Autumn 2007;

Typology: Assignments

Pre 2010

Uploaded on 09/17/2009

koofers-user-hwu
koofers-user-hwu 🇺🇸

10 documents

1 / 35

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Stat245 Recitation 18
TA: Dongmei Li
Nov. 20, 2007
TA: Dongmei Li Stat245 Recitation 18
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff
pf12
pf13
pf14
pf15
pf16
pf17
pf18
pf19
pf1a
pf1b
pf1c
pf1d
pf1e
pf1f
pf20
pf21
pf22
pf23

Partial preview of the text

Download Lecture Slides on Introduction to Statistical Analysis - Homework 10 | STAT 245 and more Assignments Data Analysis & Statistical Methods in PDF only on Docsity!

Stat245 Recitation 18

TA: Dongmei Li

Nov. 20, 2007

Announcement and Outline

I (^) Homework 10 consists of the following exercises in Chapter 10: 10.6, 10.28, 10.42, 10.56, 10.64, 10.74, and 10.82.

I (^) Exam regrades are due in recitation on Tuesday of next week.

I (^) Exam 2 Review.

I (^) Review hypothesis test for population proportion.

I (^) Problem Solving (Chapter 10).

I (^) 1. T/F A random variable is continuous if the set of possible values includes an entire interval on the number line. I (^) Answer: True.

I (^) 1. T/F A random variable is continuous if the set of possible values includes an entire interval on the number line. I (^) Answer: True.

I (^) 2. T/F The distribution of all values of a random variable is called a normal distribution.

I (^) 1. T/F A random variable is continuous if the set of possible values includes an entire interval on the number line. I (^) Answer: True.

I (^) 2. T/F The distribution of all values of a random variable is called a normal distribution. I (^) Answer: False, because only random variable that follows a symmetric, bell-shaped curve is said to have a normal distribution.

I (^) 3. T/F For every random variable, P(a ≤ x ≤ b) = P(a < x < b).

I (^) 1. T/F A random variable is continuous if the set of possible values includes an entire interval on the number line. I (^) Answer: True.

I (^) 2. T/F The distribution of all values of a random variable is called a normal distribution. I (^) Answer: False, because only random variable that follows a symmetric, bell-shaped curve is said to have a normal distribution.

I (^) 3. T/F For every random variable, P(a ≤ x ≤ b) = P(a < x < b). I (^) Answer: False, because it is only valid when x is a continuous random variable.

I (^) 4. T/F A statistic is a characteristic of the population.

I (^) Answer: False, because a statistic is a characteristic of the sample.

I (^) 4. T/F A statistic is a characteristic of the population.

I (^) Answer: False, because a statistic is a characteristic of the sample.

I (^) 5. T/F The standard deviation of the distribution of ¯x decreases as n increases.

I (^) 4. T/F A statistic is a characteristic of the population.

I (^) Answer: False, because a statistic is a characteristic of the sample.

I (^) 5. T/F The standard deviation of the distribution of ¯x decreases as n increases. I (^) Answer: True, because σ¯x = √σn (With n increase, σ¯x will

decrease.)

I (^) 6. T/F The sampling distribution of p tends to be more spread out for larger sample sizes than for smaller sample sizes.

I (^) 4. T/F A statistic is a characteristic of the population.

I (^) Answer: False, because a statistic is a characteristic of the sample.

I (^) 5. T/F The standard deviation of the distribution of ¯x decreases as n increases. I (^) Answer: True, because σ¯x = √σn (With n increase, σ¯x will

decrease.)

I (^) 6. T/F The sampling distribution of p tends to be more spread out for larger sample sizes than for smaller sample sizes.

I (^) Answer: False, because σp =

π(1−π) n (When^ n^ is large,^ σp will be small).

I (^) 7. T/F The distribution of ¯x is normal if the population is normal.

I (^) Answer: True, because the distribution of ¯x is always normal when the population has normal distribution.

I (^) 7. T/F The distribution of ¯x is normal if the population is normal.

I (^) Answer: True, because the distribution of ¯x is always normal when the population has normal distribution.

I (^) 8. T/F The distribution of ¯x will always have the same shape as the distribution of the population being sampled.

I (^) 7. T/F The distribution of ¯x is normal if the population is normal.

I (^) Answer: True, because the distribution of ¯x is always normal when the population has normal distribution.

I (^) 8. T/F The distribution of ¯x will always have the same shape as the distribution of the population being sampled. I (^) Answer: False, because When sample size is large (n > 30) the distribution of ¯x is will be normal even when the population does not has normal distribution.

I (^) 9. T/F The closer π is to 0 or 1, the larger n must be in order for the distribution of p to be approximately normal.

I (^) 7. T/F The distribution of ¯x is normal if the population is normal.

I (^) Answer: True, because the distribution of ¯x is always normal when the population has normal distribution.

I (^) 8. T/F The distribution of ¯x will always have the same shape as the distribution of the population being sampled. I (^) Answer: False, because When sample size is large (n > 30) the distribution of ¯x is will be normal even when the population does not has normal distribution.

I (^) 9. T/F The closer π is to 0 or 1, the larger n must be in order for the distribution of p to be approximately normal. I (^) Answer: True, because we need have nπ ≥ 10 and n(1 − π) ≥ 10 (n must be large when π is close to 0 or 1).