Question

In: Math

The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and...

The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 40 male consumers was $135.67, and the average expenditure in a sample survey of 35 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $39, and the standard deviation for female consumers is assumed to be $20.

  1. What is the point estimate of the difference between the population mean expenditure for males and the population mean expenditure for females (to 2 decimals)?
  2. At 99% confidence, what is the margin of error (to 2 decimals)?
  3. Develop a 99% confidence interval for the difference between the two population means (to 2 decimals). Use z-table.
    (  ,  )

Solutions

Expert Solution

Solution:

Given:

Male:

Sample size =n1 = 40

Sample mean =

Population Standard Deviation =

Female:

Sample size =n2 = 35

Sample mean =

Population Standard Deviation =

Part a) the point estimate of the difference between the population mean expenditure for males and the population mean expenditure for females

Part b) At 99% confidence, what is the margin of error

Zc is z critical value for c = 0.99 confidence level.

Find Area = ( 1+c)/2 = ( 1 + 0.99 ) / 2 = 1.99 /2 = 0.9950

Thus look in z table for Area = 0.9950 or its closest area and find corresponding z critical value.

From above table we can see area 0.9950 is in between 0.9949 and 0.9951 and both are at same distance from 0.9950, Hence corresponding z values are 2.57 and 2.58

Thus average of both z values is 2.575

Thus Zc = 2.575

Thus

Part c) Develop a 99% confidence interval for the difference between the two population means:

we have:

thus

Thus  a 99% confidence interval for the difference between the two population means is:


Related Solutions

The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 48 male consumers was $135.67, and the average expenditure in a sample survey of 34 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $35, and the standard deviation for female consumers is assumed to be $23. Develop a...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 41 male consumers was $135.67, and the average expenditure in a sample survey of 39 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $34, and the standard deviation for female consumers is assumed to be $22. a. What...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 46 male consumers was $135.67, and the average expenditure in a sample survey of 40 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $32, and the standard deviation for female consumers is assumed to be $22. What is...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 49 male consumers was $135.67, and the average expenditure in a sample survey of 31 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $36, and the standard deviation for female consumers is assumed to be $18. What is...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 43 male consumers was $135.67, and the average expenditure in a sample survey of 36 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $36, and the standard deviation for female consumers is assumed to be $24. What is...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 43 male consumers was $135.67, and the average expenditure in a sample survey of 30 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $30, and the standard deviation for female consumers is assumed to be $19. What is...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 48 male consumers was $135.67, and the average expenditure in a sample survey of 34 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $40, and the standard deviation for female consumers is assumed to be $23. What is...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 48 male consumers was $135.67, and the average expenditure in a sample survey of 34 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $40, and the standard deviation for female consumers is assumed to be $23. What is...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 40 male consumers was $135.67, and the average expenditure in a sample survey of 37 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $38, and the standard deviation for female consumers is assumed to be $19. What is...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and...
The USA Today reports that the average expenditure on Valentine's Day is $100.89. Do male and female consumers differ in the amounts they spend? The average expenditure in a sample survey of 49 male consumers was $135.67, and the average expenditure in a sample survey of 40 female consumers was $68.64. Based on past surveys, the standard deviation for male consumers is assumed to be $32, and the standard deviation for female consumers is assumed to be $20. What is...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT