Normal Table Statistics

If you select one adult at a random from this community, what is the probability that the adults is working either part - time or full - time? 

Which statement best describes the difference between data set 1 and data set 2 shown below?

• The median values are very similar, but the values in data set 2 are much more spread out since the interquartile range is larger. 

• The median values are very similar, but the values in data set 1 are much more spread out since the interquartile range is smaller. 

• The median value for data set 1 is larger, but the interquartile range is smaller, so the values in data set 1 are all larger than those in data set 2. 

• The median value for data set 2 is larger, but the interquartile range is smaller, so the values in data set 2 are all smaller than those in data set 1. 

Jamie has math test scores of 65, 90, 75, and 93. Aaron has math test scores of 98, 88, 82, and 93. How do the mean and median of Jamie’s and Aaron’s test scores compare?

• Aaron has a higher mean, but lower median test score than Jamie. 

• Jamie has a higher mean, but lower median test score than Aaron. 

• Jamie has a higher mean and median test score than Aaron.
  

• Aaron has a higher mean and median test score than Jamie. 

The prices for several items at two stores are given below. Based on this data, which statement is true?

• The standard deviation for Store X is greater than the standard deviation for Store Y by about 0.03.

• The standard deviation for Store X is greater than the standard deviation for Store Y by about 0.3.

• The standard deviation for Store X is less than the standard deviation for Store Y by about 0.03.

• The standard deviation for Store X is less than the standard deviation for Store Y by about 0.3.

The table below shows the lengths of fences a company installed during a week.  Which statement is true? 

• The 275-foot fence caused the mean to be significantly lower than the median. 

• The 275-foot fence caused the median to be significantly lower than the mean. 

• The 2,250-foot fence caused the mean to be significantly greater than the median. 

• The 2,250-foot fence caused the median to be significantly greater than the mean. 

Linda’s quiz scores are 95, 88, 98, 92, 100, and 50. If the outlier is removed, how is the shape of the distribution of the scores affected?

• The distribution will become skewed right. 

• The distribution will become skewed left. 

• The distribution will become more normal. 

• The distribution will not change. 

A normally distributed population of test scores has a mean of 80 and a standard deviation of 2.5. Find the percentage of scores that lies below 75.

• 1.39%

• 1.79%

• 2.28%

• 2.87%

Find the z-score value that corresponds to a normal random variable X = 100 in the given mean µ = 85 and standard deviation σ = 8 of a population in Statistics test.

• 1.85

• 1.86

• 1.87

• 1.88

It is a region under the normal curve. Refer to the values on table of Z-Score.

• Probability of Normal Curve

• Area of Normal Curve

• Empirical Rule

• Z-Scores

Find the area to the left of z = 1.53.

• .7093

• .3970

• .9370

• .7039