Statistics — Quiz 3

Questions in this quiz (6)

1. Each number on a list containing 50 numbers is multiplied by 5 to produce a second list containing 50 numbers. Each of the 50 numbers on the second list is increased by 3 to produce a third list of 50 numbers. The median of the third list is $$y$$. Which of the following expressions gives the median of the original list?

   • $$\frac{y-3}{5}$$
   • $$5(y-3)$$
   • $$5y-3$$
   • $$\frac{y+3}{5}$$

2. The mean of 20 numbers entered into a computer statistics program was 85. Two numbers were incorrectly entered as 82 and 90, instead of their correct values of 88 and 95, respectively. When these corrections are made, by how much will the mean increase?

   • 11
   • 6
   • 0.55
   • 6.5

3. A data set has a mean of 5, a median of 6, and an only mode of 7. If the data set contains 4 integers, which of the following statements must be true about the data set?

   • The largest integer is $$8$$.
   • One of the integers is $$9$$.
   • The sum of the $$4$$ integers is $$20$$.
   • The sum of the $$4$$ integers is $$24$$.

4. The median of a list of 9 numbers is $$y$$. In this list, 4 numbers are equal to $$y$$, and 2 numbers are less than $$y$$. If 3 additional numbers less than $$y$$ are added to the list, ensuring that $$y$$ remains the median, how many numbers in the list will be greater than $$y$$?

   • 2
   • 3
   • 4
   • 5

5. The costs of five different train tickets from Chicago to New York are shown in the table below. A sixth train line also offers service from Chicago to New York. The median price of the tickets from the six train lines, including those shown in the table, is 237 dollars. The range of the ticket prices is 40 dollars. What is the cost of the sixth train line’s ticket?

   • 296
   • 208
   • 360
   • 315

6. A scientist measures the sugar content in a random sample of 40 apples from an orchard of over 1500 apples. The sample mean sugar content is 12.4 grams, with a sampling error of 1.6 grams at a 95% confidence level. Which of the following is true, based on the sample?

   • You can be 95% confident that another sample will have a mean sugar content between 10.8 and 14.0 grams.
   • You can be 95% confident that the true population mean sugar content is between 10.8 and 14.0 grams.
   • You can be 95% confident that the standard deviation of sugar content is 1.6 grams.
   • You can be 95% confident that the true population mean is 12.4 grams.