Solve please minimal explanation require

Question 26

It is claimed that in a bushel of peaches, less than 10% are defective. A sample of 400 peaches is examined and 50 are found to be defective. What is the sample proportion?

0.10

0.125

40

0.40

Question 27

For a two-tailed test with a 0.05 significance level, where is the rejection region whennis large and the population standard deviation is known?

Between 1.960

Between 1.645

Greater than +1.960 and less than -1.96

Greater than +1.645 and less than -1.645

Question 28

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. They sampled 240 students and found a mean of 22.3 hours per week. Assuming a population standard deviation of six hours, what is the 99% level of confidence?

[21.80, 22.80]

[16.3, 28.3]

[21.30, 23.30]

[20.22, 22.0]

Question 29

A university surveyed recent graduates of the English Department for their starting salaries. Four hundred graduates returned the survey. The average salary was $25,000, with a standard deviation of $2,500. What is the best point estimate of the population mean?

$25,000

$2,500

$400

$62.5

Question 30

A university surveyed recent graduates of the English Department for their starting salaries. Four hundred graduates returned the survey. The average salary was $25,000. The population standard deviation was $2,500. What is the 95% confidence interval for the mean salary of all graduates from the English Department?

[$22,500, $27,500]

[$24,755, $25,245]

[$24,988, $25,012]

[$24,600, $25,600]

Question 32

The mean weight of trucks traveling on a particular section of I-475 is not known. A state highway inspector needs an estimate of the population mean. He selects and weighs a random sample of 49 trucks and finds the mean weight is 15.8 tons. The population standard deviation is 3.8 tons. What is the 95% confidence interval for the population mean?

14.7 and 16.9

13.2 and 17.6

10.0 and 20.0

16.1 and 18.1

Question 33

A student wanted to construct a 95% confidence interval for the mean age of students in her statistics class. She randomly selected nine students. Their average age was 19.1 years with a sample standard deviation of 1.5 years. What is the best point estimate for the population mean?

2.1 years

1.5 years

19.1 years

9 years

Question 35

A local retail company wants to estimate the mean amount spent by customers. Their store's budget limits the number of surveys to 225. What is their maximum error of the estimated mean amount spent for a 99% level of confidence and an estimated standard deviation of $10.00?

$10

$1.00

1%

$1.72

Question 36

What is the interpretation of a 96% confidence level?

There's a 96% chance that the given interval includes the true value of the population parameter.

Approximately 96 out of 100 such intervals would include the true value of the population parameter.

There's a 4% chance that the given interval does not include the true value of the population parameter.

The interval contains 96% of all sample means.

Question 38

Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The results showed that the mean tread life was 50,000 miles, with a standard deviation of 3,500 miles. What is the best estimate of the mean tread life in miles for the entire population of these tires?

50,000

3,500

500

35

Question 39

A survey of 25 grocery stores revealed that the average price of a gallon of milk was $2.98, with a standard error of $0.10. What is the 98% confidence interval to estimate the true cost of a gallon of milk?

$2.73 to $3.23

$2.85 to $3.11

$2.94 to $3.02

$2.95 to $3.01

Question 40

The mean annual incomes of certified welders are normally distributed with the mean of $50,000 and a standard deviation of $2,000. The ship building association wishes to find out whether their welders earn more or less than $50,000 annually. The alternate hypothesis is that the mean is not $50,000. Which of the following is the alternate hypothesis?

H₁: $50,000

H₁: $50,000

H₁: < $50,000

H₁: = $50,000