MODULE 4 STATISTICS QUESTIONS
AND CORRECT ANSWERS) A GRADE
To find critical value, when do you use the T table instead of Z? - ANSWERWhen the
population variance is unknown but sample variance is known
Alpha=20% the confidence interval for mu is found to be (110, 321). Which of the
following statement(s) is true? - ANSWER(b) We are 20% sure that the actual mean is
outside the range of 110 to 321.
(d) We are 80% sure that the actual mean is between 110 to 321.
Which of the following statements is correct? - ANSWERPoint estimate of population
mean is sample mean
How large a sample is necessary if we wish to estimate 95% confidence interval which
is accurate within 25% and population standard deviation is known to be 2 years. -
ANSWER246
For the 95% confidence interval of mean sample size is 9 (sigma unknown). what is t-
alpha over 2 (Critical value)? - ANSWER2.306
For 5 degrees of freedom and 95% confidence level what are the two critical values
(Chi-Square_(1-alpha/2) and Chi-Square_(alpha/2)) from chi-square table? -
ANSWERChi-Square_(1-alpha/2)=0.831
Chi-Square_(alpha/2) =12.833
A company is interested on average wages of employee and variance. A sample of 20
workers is taken and it is found that mean wage was $9.5 and sample standard
deviation was. $1.30. Construct a 95% confidence interval for the population variance. -
ANSWER(0.977, 3.605)
A random sample of 250 families in City A revealed that 65 families had annual income
over $100,000. Another random sample of 300 family from city B contained 45 families
had annual income over $100,000. Find the point estimate of the difference of
proportion between City A and City B. - ANSWER0.11
Bowling league members bowled at two different locations. At the location with oiled
lane a sample of 35 bowling has mean score 205.5 and sample standard deviation 25.4.
on the other hand, at the location with dry lanes, a sample of 35 bowling has mean
AND CORRECT ANSWERS) A GRADE
To find critical value, when do you use the T table instead of Z? - ANSWERWhen the
population variance is unknown but sample variance is known
Alpha=20% the confidence interval for mu is found to be (110, 321). Which of the
following statement(s) is true? - ANSWER(b) We are 20% sure that the actual mean is
outside the range of 110 to 321.
(d) We are 80% sure that the actual mean is between 110 to 321.
Which of the following statements is correct? - ANSWERPoint estimate of population
mean is sample mean
How large a sample is necessary if we wish to estimate 95% confidence interval which
is accurate within 25% and population standard deviation is known to be 2 years. -
ANSWER246
For the 95% confidence interval of mean sample size is 9 (sigma unknown). what is t-
alpha over 2 (Critical value)? - ANSWER2.306
For 5 degrees of freedom and 95% confidence level what are the two critical values
(Chi-Square_(1-alpha/2) and Chi-Square_(alpha/2)) from chi-square table? -
ANSWERChi-Square_(1-alpha/2)=0.831
Chi-Square_(alpha/2) =12.833
A company is interested on average wages of employee and variance. A sample of 20
workers is taken and it is found that mean wage was $9.5 and sample standard
deviation was. $1.30. Construct a 95% confidence interval for the population variance. -
ANSWER(0.977, 3.605)
A random sample of 250 families in City A revealed that 65 families had annual income
over $100,000. Another random sample of 300 family from city B contained 45 families
had annual income over $100,000. Find the point estimate of the difference of
proportion between City A and City B. - ANSWER0.11
Bowling league members bowled at two different locations. At the location with oiled
lane a sample of 35 bowling has mean score 205.5 and sample standard deviation 25.4.
on the other hand, at the location with dry lanes, a sample of 35 bowling has mean
