Bellwork March 7

The manager of a restaurant wants to find out diner’s opinions on several matters by surveying a random sample of the restaurant goers. Resources will only allow 300 diners to be surveyed. Which method of choosing a sample would allow the manager to draw the most valid conclusions based on the results?

• . Survey the first 100 diners who arrive at the restaurant first for three weeks in a row

• Survey 300 diners at random drawn from a lottery.

• . Survey the first 300 diners who respond to a flyer to be surveyed in exchange for a gift card.

• Survey the first 300 diners whose bill was over $25.

Which method would be the best way to conduct an observational study to determine the effects of Vitamin D for strengthening bones?

• Ask 100 people who take Vitamin D if they have strong bones.

• . Ask 100 people who do not have strong bones if they take Vitamin D on a regular basis and record the results.

• Divide 100 people into two groups: one group will take Vitamin D and the other group will not. After a period, see how many people in each group have strong bones.

• Interview 100 people and classify them as either Never Consuming Vitamin D, Sometimes Consuming Vitamin D, or Consuming Vitamin D on a Regular Basis. Check for strong bones in all the patients and analyze the results.

. A tire center wants to conduct a survey about client satisfaction. Which of the following methods should be used to reduce the chance of bias?

• Randomly select 250 clients in the age group 30 – 45 and ask them to rate the service they received.

• Randomly select 250 clients and ask them to rate the service they received.

• Randomly select 500 truck drivers and ask them to rate the service they received.

• Choose the first 25 clients over a weekend period and ask them to rate the service they received.

What is the z-score of a data point that is 2 standard deviations above the mean in a normal distribution?

• 0.5

• 1

• 2

• 3

The heights of students in a class follow a normal distribution with a mean of 65 inches and a standard deviation of 3 inches. John is 70 inches tall, while Sarah is 67 inches tall. Calculate the z-scores for John and Sarah and determine who is taller than their peers.

• John is relatively taller than Sarah.

• Sarah is relatively taller than John.

• John and Sarah are equally tall.

• insufficient information to determine who is relatively taller.

Consider two exponential functions:

f(𝑥) = 2(3)^x

𝑔(𝑥) = 100(0.5)^x

Which of the following statements is true about these functions?

• Both represent growth

• Both represent decay

• F(x) represents growth and g(x) represents decay

• F(x) represents decay and g(x) represents growth