Math 11 Midterm 1

A woman’s DNA matches that of a sample found at a crime scene. If the woman is guilty the chances of a DNA match is virtually 100% (i.e. the chance of a false negative is essentially zero). Can we say that given a DNA match, the woman must be guilty?

• Yes

• No

A woman’s DNA matches that of a sample found at a crime scene. There is 70% chance she committed the crime. A DNA test has a false positive rate of 40%. What is the probability she is guilty?

• 0.4

• 0.7

Based on this plot, can we conclude that having a bachelor's

degree increases one's income?

• Yes

• No

You flip a coin 12 times with an 80% probability of heads. What is the probability of at least one tails in the 12 flips?

Which of the grade distributions is not a valid probability distribution?

• (d) , (f)

• (c),(d), (f)

• (a), (c), (d),(f)

• (a), (c), (d), (e), (f)

Which boxplot best matches histogram (a)?

• 1

• 2

• 3

Which plot depicts a high leverage point that is not influential?

• a

• b

• c

Do you expect the mean to be greater or less than the median based on this histogram?

• Greater

• Less than

Match the correlations and the plots

• 1. R = 0.92

  2. R = 0.45

  3. R = 0.06

  4. R = -0.7

• 1. R = 0.06

  2. R = 0.92

  3. R = 0.45

  4. R = -0.7

• 1. R = -0.07

  2. R = 0.92

  3. R = 0.06

  4. R = 0.46

• 1. R = 0.06

  2. R = 0.45

  3. R = 0.92

  4. R = -0.7

Suppose you want to estimate the percentage of videos on YouTube that are cat

videos. It is impossible for you to watch all videos on YouTube so you use a random video picker to select

1000 videos for you. You find that 2% of these videos are cat videos. Determine which of the following is a sample statistic?

• Percentage of all videos on YouTube that are cat videos.

• 2%

• A video in your sample

• Whether or not a video is a cat video