Statistics Trivia Quiz: Can You Pass This Advanced Placement Exam?

1) The correlation between height in inches and weight in pounds for a particular class is 0.65. If the heights are converted from inches to centimeters, what will the correlation be? (1 in. = 2.54 cm)

-0.65

-0.26

0.10

0.26

0.65

When the heights are converted from inches to centimeters, the numerical values of the heights will change, but the relationship between height and weight will remain the same. Therefore, the correlation between height in centimeters and weight in pounds will also be 0.65.

Explanation

When the heights are converted from inches to centimeters, the numerical values of the heights will change, but the relationship between height and weight will remain the same. Therefore, the correlation between height in centimeters and weight in pounds will also be 0.65.

2) Researchers in the Southwest studying tortoise habitat collected the following data. If a tortoise is selected at random, let A = the tortoise is a female, and B = the tortoise is a Morafka. Which answer appropriately interprets the value of P(B|A)?

Species	Male	Female
Agassiz	18	33
Morafka	12	15

31.3% is the probability that a randomly selected Morafka tortoise is a female tortoise.

31.3% is the probability that a randomly selected female tortoise is a Morafka tortoise.

19.2% is the probability that a randomly selected Morafka tortoise is a female tortoise.

19.2% is the probability that a randomly selected female tortoise is a Morafka tortoise.

31.3% is the probability that a randomly selected tortoise is a female tortoise.

The value of P(B|A) represents the probability that a randomly selected female tortoise is a Morafka tortoise. In the given data, there are 15 female Morafka tortoises out of a total of 48 female tortoises. Therefore, the probability is calculated as 15/48 = 31.3%.

Explanation

The value of P(B|A) represents the probability that a randomly selected female tortoise is a Morafka tortoise. In the given data, there are 15 female Morafka tortoises out of a total of 48 female tortoises. Therefore, the probability is calculated as 15/48 = 31.3%.

3) A spreadsheet contains a data set that consists of 100 values such that IQR > variance. However, these values must be converted using the following formula: NewValue = 2(OldValue)+10. Which of the following statements is true about the data set consisting of the NewValues?

The IQR has been increased by 10 units.

The IQR is now less than the variance.

The IQR is now double its previous size.

The IQR has been doubled and then increased by 10 units.

The IQR has been cut in half.

The given formula, NewValue = 2(OldValue)+10, doubles each value in the data set and adds 10 to it. Since the IQR is a measure of the spread of the middle 50% of the data, doubling each value will also double the range between the 25th and 75th percentiles, resulting in the IQR being double its previous size.

Explanation

The given formula, NewValue = 2(OldValue)+10, doubles each value in the data set and adds 10 to it. Since the IQR is a measure of the spread of the middle 50% of the data, doubling each value will also double the range between the 25th and 75th percentiles, resulting in the IQR being double its previous size.

4) Researchers wish to test how rangelands growth is affected by wildfire. A very large open area is divided into 28 equally sized plots and subjected to a controlled burn. One year later, the researchers calculate the percentage of grass returned in each plot after the fire damage. The average percentage return for these 28 plots was 58.5% with a standard deviation of 6.5%. Which of the following represents a 95% confidence interval to estimate the average proportion of grass return one year after fire?

A

B

C

D

E

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Explanation

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5) Which of the following is not an advantage of stratified random sampling over simple random sampling?

When done correctly, a stratified random sampling process has less variability from sample to sample than a simple random sample.

When done correctly, a stratified random sample is less biased than a simple random sample.

This answer states that a stratified random sample is less biased than a simple random sample. This means that when using stratified random sampling, the sample is more representative of the population, reducing the potential for bias in the results. This is an advantage of stratified random sampling over simple random sampling, as simple random sampling may have a higher likelihood of introducing bias into the sample.

Explanation

This answer states that a stratified random sample is less biased than a simple random sample. This means that when using stratified random sampling, the sample is more representative of the population, reducing the potential for bias in the results. This is an advantage of stratified random sampling over simple random sampling, as simple random sampling may have a higher likelihood of introducing bias into the sample.