AP Stats Chapter 3

The distribution of actual weights of 8.0-ounce chocolate bars produced by a certain machine is normal with a mean of 8.1 ounces and a standard deviation of 0.1 ounces. The proportion of chocolate bars weighing less than or equal to 8.0 ounces is:

• 0.159

• 0.341

• 0.500

• 0.659

• 0.841

A study found a correlation of r = 0.61 between the age of an employee and his or her income. You may correctly conclude that:

• An increase in an employee’s age causes an increase in their income.

• As an employee’s age increases, their income tends to increase.

• There is no association between an employee's age and his or her income.

• As an employee’s age increases, their income tends to decrease.

• There is a 61% change we can accurately predict an employee’s income if we know their age.

• Positive, strong
• Positive, weak
• Negative, strong
• Negative, weak

• Positive, strong
• Positive, weak
• Negative, strong
• Negative weak

• Positive, strong
• Positive, moderate
• Negative, strong
• Negative, moderate

• Positive, strong
• Positive, weak
• Negative, strong
• Negative weak

Rank these scatter plots according to the intensity of the correlation represented, from weakest to strongest.

• 1, 2, 3, 4

• 2, 4, 3, 1

• 4, 3, 2, 1

• 1, 3, 4, 2

What kind of correlation?

• Positive

• Negative

• No significant correlation

Estimate the value of r:

• 0.99

• 0.05

• -0.99

What is the slope of the LSRL from this printout?

• 0.74

• -0.47

• 1.098

• 23.59