Whether confounding is an issue with this study or not.

Kaycee Roche
2021-02-11
Answered

Whether confounding is an issue with this study or not.

You can still ask an expert for help

Dora

Answered 2021-02-12
Author has **98** answers

In the study, design firm uses one page in Denver area and the second page in Miami area. It is possible that one area may be cold and the other may be sunny. People usually use hardware in the sunny season. Therefore, the visiting time and money spent by a visitor will be high in the sunny area.

asked 2021-01-31

The centers for Disease Control reported the percentage of people 18 years of age and older who smoke (CDC website, December 14, 2014). Suppose that a study designed to collect new data on smokers and Questions Navigation Menu preliminary estimate of the proportion who smoke of .26.

a) How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of .02?(to the nearest whole number) Use 95% confidence.

b) Assume that the study uses your sample size recommendation in part (a) and finds 520 smokers. What is the point estimate of the proportion of smokers in the population (to 4 decimals)?

c) What is the 95% confidence interval for the proportion of smokers in the population?(to 4 decimals)?

a) How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of .02?(to the nearest whole number) Use 95% confidence.

b) Assume that the study uses your sample size recommendation in part (a) and finds 520 smokers. What is the point estimate of the proportion of smokers in the population (to 4 decimals)?

c) What is the 95% confidence interval for the proportion of smokers in the population?(to 4 decimals)?

asked 2020-11-22

Answer true or false to each statement.

a. Two normal distributions that have the same mean are centered at the same place, regardless of the relationship between their standard deviations.

b. Two normal distributions that have the same standard deviation have the same spread, regardless of the relationship between their means.

a. Two normal distributions that have the same mean are centered at the same place, regardless of the relationship between their standard deviations.

b. Two normal distributions that have the same standard deviation have the same spread, regardless of the relationship between their means.

asked 2021-09-09

Choose the right answer for the question: "Regardless of individual seat-belt use, does living in a community with strict auto-safety laws affect individual risk of auto-related mortality?”

a) experimental study design

b) ecological study design

c) contextual or multi-level study design

d) case-control study design

a) experimental study design

b) ecological study design

c) contextual or multi-level study design

d) case-control study design

asked 2021-12-05

Suppose that the number of car accidents per day in Wilmington, NC has been recorded for the past year. The table below is a probability distribution table representing the data collected.

$$\overline{)\begin{array}{cccccc}\text{Number of accidnets}& 0& 1& 2& 3& 4\\ Probability& & .12& .32& .25& .13\end{array}}$$

b) Find the probability that there will be at least 2 accidents

b) Find the probability that there will be at least 2 accidents

asked 2021-11-27

The following data represent the planned rated capacities in megawatts (millions of watts) for the world’s 20 largest hydroelectric plants.

See Attachment

a. Construct a stem and leaf display for the data.

b. How would you describe the shape of this distribution?

$$\begin{array}{|ccc|}\hline 18,200& 4,500& 3,000\\ 12,600& 4,200& 2,940\\ 10,000& 4,200& 2,715\\ 8,370& 3,840& 2,700\\ 6,400& 3,444& 2,541\\ 6,300& 3,300& 2,512\\ 6,000& 3,100\\ \hline\end{array}$$

See Attachment

a. Construct a stem and leaf display for the data.

b. How would you describe the shape of this distribution?

asked 2021-12-05

The mean number of birth of babies over a 7 month period in lbri is 106 and the coefficient of variation of the data is 5.21%. Find the standard deviation of the data.

1) 5.5226

2) 7.0226

3) 4.5226

4) 6.5226

1) 5.5226

2) 7.0226

3) 4.5226

4) 6.5226

asked 2022-07-22

The average score on your Math Exams was 75 with a standard deviation of 20. Assuming the scores are normally distributed. If your corresponding z-score was 1.5, and your corresponding raw score is 105, what is the percentile rank?