# 0.2 Practice tests (1-4) and final exams  (Page 20/36)

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62 . What would be your decision, if you were using α = 0.01?

## 10.3: comparing two independent population proportions

Use the information to answer the next six exercises. You want to know if proportion of homes with cable television service differs between Community A and Community B. To test this, you draw a random sample of 100 for each and record whether they have cable service.

63 . What are the null and alternative hypotheses for this study

64 . If 65 households in Community A have cable service, and 78 households in community B, what is the pooled proportion?

65 . At α = 0.03, will you reject the null hypothesis? What is your conclusion? 65 households in Community A have cable service, and 78 households in community B. 100 households in each community were surveyed.

66 . Using an alpha value of 0.01, would you reject the null hypothesis? What is your conclusion? 65 households in Community A have cable service, and 78 households in community B. 100 households in each community were surveyed.

## 10.4: matched or paired samples

Use the following information to answer the next five exercises. You are interested in whether a particular exercise program helps people lose weight. You conduct a study in which you weigh the participants at the start of the study, and again at the conclusion, after they have participated in the exercise program for six months. You compare the results using a matched-pairs t-test, in which the data is {weight at conclusion – weight at start}. You believe that, on average, the participants will have lost weight after six months on the exercise program.

67 . What are the null and alternative hypotheses for this study?

68 . Calculate the test statistic, assuming that ${\overline{x}}_{d}$ = –5, s d = 6, and n = 30 (pairs).

69 . What are the degrees of freedom for this statistic?

70 . Using α = 0.05, what is your decision regarding the effectiveness of this program in causing weight loss? What is the conclusion?

71 . What would it mean if the t -statistic had been 4.56, and what would have been your decision in that case?

## 11.1: facts about the chi-square distribution

72 . What is the mean and standard deviation for a chi-square distribution with 20 degrees of freedom?

## 11.2: goodness-of-fit test

Use the following information to answer the next four exercises. Nationally, about 66 percent of high school graduates enroll in higher education. You perform a chi-square goodness of fit test to see if this same proportion applies to your high school’s most recent graduating class of 200. Your null hypothesis is that the national distribution also applies to your high school.

73 . What are the expected numbers of students from your high school graduating class enrolled and not enrolled in higher education?

74 . Fill out the rest of this table.

Observed ( O ) Expected ( E ) O E ( O E )2 $\frac{{\left(O-E\right)}^{2}}{z}$
Enrolled 145
Not enrolled 55

75 . What are the degrees of freedom for this chi-square test?

76 . What is the chi-square test statistic and the p -value. At the 5% significance level, what do you conclude?

77 . For a chi-square distribution with 92 degrees of freedom, the curve _____________.

the mean of random variable following binomial distribution is 10. the numbers of trails are 30. What the approximate value of variance?
what is chis square
A chi-square (χ2) statistic is a test that measures how a model compares to actual observed data.
kalim
descriptive statistics basic
Sangeetha
Hi Friends
Sangeetha
tamil people yaaraavathu irukkingala
Sangeetha
what is the median of the following set of number:3,3,3,4,5,6,7,8,8,9?
3
Mbemah
5.6
Alekya
(5+6)/2=5.5555.......=5.6
Lyrical
(5+6)/2=5.5 that is the median
moniba
hi friends am new here, hope am welcome
nathan
hi friends am new here, hope am welcome
nathan
1.5
nathan
differences between Intervals and Ratio measurement scales
interval is the distinct from a starting point to the peak of a certain distance
Mbemah
the taking of a certain range accurately in a divisional way
Mbemah
i need the solution for exercise sums
descriptive statistics sums I need
Sangeetha
statistics discovered?
internet
Kamranali
dev OS
Virendra
searching for motivation to learn stat
Nija
purpose of of statistics
mukesh
ya..
mukesh
tamil people yaraavathu inrukkingala
Sangeetha
Odisha ru kau bhai mane achha?
Hemanta
I want to learn my MSC by statistics who can help me ?
Abebe
@Avirup interest person
Abebe
good morning
Sangeetha
Dr good morning
mukhtar
in statistical inferences we use population parameter to infer sample statistics
Yes
lukman
how do we calculate decile
how do we calculate class boundaries
Syed
The lower class boundary is found by subtracting 0.5 units from the lowerclass limit and the upper class boundary is found by adding 0.5 units to the upper class limit. The difference between the upper and lowerboundaries of any class.
Ekene
The lower class boundary is found by subtracting 0.5 units from the lowerclass limit and the upper class boundary is found by adding 0.5 units to the upper class limit. The difference between the upper and lowerboundaries of any class.
Ekene
complete definition plz
the average increase for all NASDAQ stocks is the
formula of poisson probability distribution
frequency distribution table
Girma
sum of dots when 2 dice are rolled is
what is statistics?
Statistics is the collection of methods for planning experiments, obtaining data, and then organizing, summarizing, presenting, analyzing, interpreting, and drawing conclusions.
John
you are right
razia
you are right
razia