Tuesday

September 30, 2014

September 30, 2014

Posted by **Andrea** on Wednesday, January 28, 2009 at 8:08pm.

A recent poll of 700 people who work indoors found that 278 of them smoke.If the researchers want to be 98% confident of thier results to within 3.5%, how large a sample is necessary?

- College Statistics 2 -
**MathGuru**, Wednesday, January 28, 2009 at 10:17pmHere's one formula you can use for a problem of this type:

n = [(z-value)^2 * p * q]/E^2

Note: n = sample size needed; ^2 = squared; .4 for p and .6 for q (q = 1 - p). E = maximum error, which is .035 (3.5%) in the problem. Z-value is found using a z-table (find the value that corresponds to 98% confidence). Substitute into the formula. Round your answer to the next highest whole number.

Note: 278/700 is approximately .4 in decimal form.

I hope this will help.

- Elementary Statistics -
**Roxanne Singleton**, Monday, November 2, 2009 at 9:46am2. A research team studied the ages of patients who had heart attacks caused by smoking. The ages of 34 patients who suffered a heart attack were as follows.

29 30 36 41 45 50 57 61 28 50 66 58

60 38 36 47 40 32 58 46 61 40 55 32

61 56 45 46 62 66 38 40 40 27

Construct a Stem-and-Leaf Plot using this data with Key: 5 | 7 = 57.

**Answer this Question**

**Related Questions**

statistics - An employer polled its employers to see if they agree with the ...

statistics - a recent poll of 700 peole who work indoors found that 278 of the ...

Statistics - In a poll of 1,000 adults, 57% believed that there was too much ...

College Physics - The point charges in Figure 17.41 are located at the corners ...

Statistics - A recent survey of students on the question “Do you think the ...

statistics - in 1995,the gallup poll asked a sample of 620 adults whether their ...

College Algebra - find the eqauation for this problem Basketball Scroing- The ...

maths - number of films seen by a group of people during the past year No of ...

Statistics - A recent Gallup Poll dealt with the proportion of Canadians who ...

statistics - A researcher wishes to estimate the proportion of college students...