Biology Forums - Study Force

The width of the one-sample confidence interval for  decreases as the sample size grows larger.
  1.True
  2.False

Q. 2

The confidence interval formula for estimating  when n is large is based on the Central Limit Theorem.
  1.True
  2.False

Q. 3

Suppose you are instructed to create the seldom used 85 confidence for the difference between two proportions. What is the value of the confidence coefficient?
  1.1.04
  2.1.44
  3.0.19
  4.0.30

Q. 4

Use the following statistical output for a difference between two-proportions to determine the upper bound of the 95 confidence interval.
  <--EndFragment--> ence level.
   CI for Two Proportions
   Sample X N Sample p
   1 30 40 0.750000
   2 13 20 0.650000
   Difference = p (1) - p (2)
   Estimate for difference: 0.1
   95 CI for difference: (-0.1484, _______)
   
  1.0.1481
  2.-0.0484
  3.0.3484
  4.0.1000

Q. 5

A study seeks to determine whether the proportion of Dutch boys who listen to music at high volume is greater than this proportion for Dutch girls. After checking to make sure that all of the necessary conditions were met, we calculated the value of the z test statistic to be z = 2.999. Which of the following is the P-value associated with this test?
  1.0
  2.0.0014
  3.0.0028
  4.0.9986
  5.0.9972

Q. 6

A study is conducted to determine whether the proportion of airline passengers complaining with post-flight respiratory symptoms is larger for flights that do not circulate cabin air than for flights that do circulate the air. After checking to make sure that all of the necessary conditions were met, we calculated the value of the z test statistic to be z = 0.84. Which of the following is the P-value associated with this test?
  1.0
  2.0.2005
  3.0.401
  4.0.7995
  5.0.599

Q. 7

To learn about the proportion of college students who are registered to vote, surveys were conducted in 2010 and in 2011. Suppose that in 2010, 39 of the people in a representative sample of 450 college students were registered to vote. In 2011, 33 of the people in a representative sample of 235 college students were registered to vote. For the 99 confidence level, determine the margin of error of the difference of the proportions.
  1.0.0751
  2.0.0495
  3.0.0989
  4.0.4131
  5.0.0383

Q. 8

A study determined that in 2009, 38 of those in a random sample of 100 adult Americans had accounts with some type of social web site. In a similar survey conducted in 2012, 53 reported having accounts. Suppose that the 2012 figure was also based on a random sample of size 100. The 95 confidence interval for the difference in population proportions, , is: <--EndFragment--> >
  1.0.15  0.088
  2.0.29  0.136
  3.0.15  0.136
  4.0.29  0.88
  5.0.00  0.136

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