How would a 90​% interval compare with the others in​ width?   A. A 90​% interval would be narrower than the 95​% confidence interval but wider than the 80​% confidence because intervals get narrower with increasing confidence level.   B. A 90​% interval would be wider than the 95​% confidence interval but narrower than the 80​% confidence because intervals get narrower with increasing confidence level   C. A 90​% interval would be wider than the 95​% confidence interval but narrower than the 80​% confidence because intervals get wider with increasing confidence level.   D. A 90​% interval would be narrower than the 95​% confidence interval but wider than the 80​% confidence because intervals get wider with increasing confidence level.

Thelma and Louise are each attempting to estimate the proportion of adults who enjoy listening to country music.  They each survey a different random sample of adults, and in each sample, the proportion who say they enjoy listening to country music is 0.29.   Thelma and Louise each use their sample data to construct a confidence interval.  Thelma’s interval is from 0.242 to 0.338 and Louise’s interval is from 0.237 to 0.323.  One of these intervals was computed correctly and the other was not.  Which interval must be the correct one?

If two people used the same data and one person made a 90% confidence interval and the other person made a 95% confidence interval for p, which interval would be more narrow?   is it; a. The 90% Confidence interval b. The 95% Confidence interval c. We cannot tell from the information alone.

Ellie and Alec are each attempting to estimate the proportion of coffee drinkers who consume more than one cup of coffee per day. They each obtain a random sample of coffee drinkers, and, in each sample, the proportion who drink more than one cup of coffee per day is 0.40. Ellie and Alec each use their sample data to construct a confidence interval. Ellie’s interval is from 0.286 to 0.514, and Alec’s interval is from 0.346 to 0.474. One of these intervals was computed correctly, but the other was not. Which interval must be incorrect? A. Ellie’s interval must be incorrect. B. Alec’s interval must be incorrect. C. It’s impossible to answer this question without knowing the level of confidence used for each interval. D. It’s impossible to answer this question without knowing the sample sizes. E. It’s impossible to answer this question without knowing the sample sizes or the level of confidence used for each interval.

A study was done of 6 patients admitted to a hospital. Their ages (x) and systolic blood pressure (y) was recorded. Systolic blood pressure (y) Age (x) 43 123 48 125 56 135 61 143 67 145 70 152 Determine the equation of the regression equation, reporting each to 3 decimal places. A. Slope is B. Y intercept is C. Compute the residual for x = 43, using the rounded slope and y intercept. Report answer to 3 decimal places.

A researcher wanted to check whether the percentage of Canadian adults with obesity has decreased in 2009 compared to 2005. He used Health Canada data. He randomly selected 75 Canadian adults from 2005 data and found 12 of them are obese; In a random sample of 120 Canadian adults from 2009 data, he found 17 of them are obese. He wants to develop a 96% confidence interval for the change is obese percentage. Let population1 be 2005 data and population2 be 2009 data. Write down the critical value.

We survey a random sample of American River College students and ask if they drink coffee on a regular basis. The 90% confidence interval for the proportion of all American River College students who drink coffee on a regular basis is (0.262, 0.438). What will be true about the 95% confidence interval for these data? 1. The 95% confidence interval is narrower than the 90% confidence interval.   2. The 95% confidence interval is wider than the 90% confidence interval.   3. The two intervals will have the same width.   4. It is impossible to say which interval will be wider.

In question above a 99% confidence interval was computed. If the confidence level were decreased to 90%, what impact would this have on the margin of error and width of the confidence interval? Both the margin of error and the width would increase. The margin of error would increase and the width would decrease The margin of error would decrease and the width would increase. Both the margin of error and the width would decrease. Neither the margin of error nor the width would be affected.

A traffic engineer wishes to determine whether cell phone use while driving causes subjects to speed. The engineer has organized for subjects' friends to call while they are driving on a highway and then records their speeds before, during, and after the call. A test is performed on the following hypothesis: Ho : Pphone = Pno phone Ha : Pphone 7 Pno phone Define Pphone as the proportion who speed while on the phone and Pao phone as the proportion who speed while not on the phone. If this test yields a p-value of 0.0782, which of the following conclusions can be made?

One researcher finds a 95% confidence interval for a prevalence of heart disease in a population as centered at 26.2 percent with margin of error 4.2 percent, and another finds a 90% confidence interval centered at 32.1 percent with margin of error 3.6 percent. Can both be accurate? Why or why not? Yes, because they have different levels of confidence. O No, because the results differ by too much. No, because they have different levels of confidence. Yes, because the confidence intervals overlap. No, because they have different margins of error.