# statistics

posted by .

A major taxi company is concerned that its proportion of late arrivals has substantially increased in the past month. Historical data shows that on the average 18% of the company taxis have arrived late. In a random sample of 1,240 taxis, 310 taxis have arrived late. If we are conducting a hypothesis test of a single proportion to determine if the proportion of late arrivals has increased: What is the value of the calculated test statistic?

• statistics -

Using a formula for a binomial proportion one-sample z-test with your data included, we have:

z = .25 - .18 -->test value (310/1240 = .25) minus population value (.18)
divided by
√[(.18)(.82)/1240] -->.18 is test value, .82 is 1 - .18, and 1240 is the sample size

Finish the calculation for the value of the test statistic.

• statistics -

6.416

## Similar Questions

1. ### English

Which of the following is a simple sentence?
2. ### english

Which of these is a simple sentence and why?
3. ### statistics

"Separate the data by company and do descriptive stats for each. Copy and paste into a Word document, formatting appropriately. “Appropriate” includes formatting to a reasonable and appropriate number of decimals, including a good, …
4. ### math

An airline tracks data on its flight arrivals. Over the past six months, 25 flights on one route arrived early, 150 arrived on time, 45 were late, and 30 were cancelled. a. What is the probability that a flight is early?
5. ### Statistic

A major airline company is concerned that its proportion of late arrivals has substantially increased in the past month. Historical data shows that 18% of the company airplanes have arrived late. In a random sample of 1,240 airplanes, …
6. ### English

Which of the following is a simple sentence?
7. ### math

Question 1 Production Rates A manufacturing company wishes to estimate the number of items that its workforce can produce on average each hour now that they have a new machine. The factory examined the records for a random sample of …
8. ### Data Analysis

A) An insurance company wants to estimate the proportion of people unsatisfied with their new telephone help service. A survey of 200 callers revealed 45 were unsatisfied with the service. Construct by hand a 95% confidence interval …
9. ### Data Analyse

Question 1 Production Rates A manufacturing company wishes to estimate the number of items that its workforce can produce on average each hour now that they have a new machine. The factory examined the records for a random sample of …
10. ### Data analysis

Question 1 Production Rates A manufacturing company wishes to find out whether the productivity of its workforce has increased now that they have a new machine. The factory examined the records for a random sample of 8 hours over the …

More Similar Questions