Variability and Sampling
The Normal Distribution
Margin of Error
Analysis of Data
Grab Bag
100
This investigation technique is most often used to determine if a single variable has an impact on a given population.
What is a controlled experiment?
100
In a normal distribution, this percentage represents the amount of data values found one standard deviation away from the mean.
What is 68%
100
A company wishes to determine the cooking time for one pound of spaghetti. The company's technicians cooked one pound of spaghetti ad recorded the time needed for the spaghetti to be ready to eat. Repeating this process 35 times resulted in an approximately normal distribution with a mean of 9.82 and a standard deviation of 1.4 minutes. This is the interval where 95% of the cooking times fall.
What is 7.02 - 12.62?
100
An orange juice processing plant receives a truckload of oranges. The quality control team randomly chooses three pails of oranges, each containing 50 oranges, from the truckload. These are the sample and the population.
What is the three pails of oranges and the truckload of oranges?
100
The function N(x)=90(0.86)x+69 can be used to predict the temperature of a cup of hot chocolate in degrees F after x minutes. This is the rate of change of the temperature of hot chocolate in degrees per minute over the interval [0, 6], rounded to the nearest hundredth.
What is -8.93 degrees per minute?
200
A sociologist reviews randomly selected surveillance videos from a public part over a period of several years and records the amount of time people spent on a smart phone. This is the statistical procedure used by the sociologist.
What is an observational study?
200
The heights of women in the United States are normally distributed with a mean of 64 inches and a standard deviation of 2.75 inches. this is the percent of women whose heights are between 64 and 69.5 inches, to the nearest whole percent.
What is 48%?
200
In a packaging plant, a machine packs boxes with jars. The machine's manufacturer states that a box is packed, on average, every 42 seconds. To test this claim, the packaging plant randomly selects a sample of 10 boxes and finds the sample mean to be 49.8 seconds. The company ran a simulation of 1000 trials based on the manufacturer's claim. Based on the simulation, this is the interval containing the middle 95% of plausible mean times, rounded to the nearest hundredth.
What is 35.82 - 48.24
200
In an attempt to get the student body's opinion of a new dress code, members of the statistics class surveyed the students of the first period computer science class. This is the statistical bias in the method of collection.
What is the fact that the first period computer science class is not representative of the population?
200
This is the expression below in simplest a+bi form
i^2(5x-2i)^2
What is
-25x^2+4+20x*i
300
When conducting a controlled experiment to study a new weight loss drug, this type of variability would cause people to lose different amounts of weight.
What is natural variability?
300
The monthly unemployment rate of towns in the United States is approximately normally distributed with a mean rate of 5.2% and a standard deviation of 1.6%. This is the percentage of towns, to the nearest integer, that have a monthly unemployment rate greater than 6%.
What is 31%
300
In a packaging plant, a machine packs boxes with jars. The machine's manufacturer states that a box is packed, on average, every 42 seconds. To test this claim, the packaging plant randomly selects a sample of 10 boxes and finds the sample mean to be 49.8 seconds. The company ran a simulation of 1000 trials based on the manufacturer's claim. Based on the simulation, this would be the conclusion about a packaging time of 49.8 seconds
What is that it is unusual becuase it falls outside of the margin of error.
300
A grocery story orders 50 bags of oranges from a company's distribution center. The bags have a mean weight of 3.85 pounds per bag. The company claims that their bags of oranges have a mean weight of 4 pounds. The grocery story ran a simulation of 50 bags, 2500 times, assuming a mean of 4 pounds. This would be the conclusion about whether or not the mean weight of the grocery store's sample is unusal.
What is it is unusual because it falls outside of the margin of error?
300
This is the factored form of 8b^3-125
What is (2b-5)(4b^2+10b+25)?
400
A difference in sample means may be caused by a treatment OR this kind of variability.
What is sampling variability?
400
The heights of the 3300 students at Oceanview High School are approximately normally distributed with a mean of 65.5 inches and a standard deviation of 2.9 inches. This is the number of students at Oceanview who are between 64 and 68 inches tall.
What is 1660
400
Betty conducted a survey of her class to see if they like pizza. She gathered 200 responses and 65% of the voters said they did like pizza. Betty then ran a simulation of 400 more surveys, each with 200 responses, assuming that 65% of the voters would like pizza. She found the mean to be 0.654 and the SD to be 0.035. This is the margin of error.
What is 0.07?
400
An app design company believes that the proportion of high school students who have purchased apps on their smartphones in the past 3 months is 0.85. A simulation of 500 samples of 150 students was run based on this proportion. Suppose a sample of 150 students from your high school showed that 88% of students had purchased apps on their smartphones in the past 3 months. This would be the evidence to show that the results from your high school give the app design company reason to believe their assumption is correct.
What is a proportion of 88% falls inside the margin of error (79% - 91%)
400
This is the solution(s) to the equation below
sqrt(x+1)-1=x
What is 0 and -1?
500
This term describes a systematic error induced into sampling or testing that skews results away from the true values.
What is bias?
500
The scores on a mathematics college-entry exam are normally distributed with a mean of 68 and standard deviation 7.2. Students scoring higher than one standard deviation above the mean will not be enrolled in the mathematics tutoring program. This is the number of the 750 incoming students that can be expected to be enrolled in the tutoring program.
What is 119?
500
A study conducted in 2004 in New York City found that 212 out of 1334 participants had hypertension. Kim ran a simulation of 100 studies based on these data. At a 95% confidence level, this is the margin of error rounded to the nearest hundredth.
What is .01?
500
A teacher wants to see if grading homework has an effect on test scores. Describe how she can design a controlled experiment to determine this.
The teacher can randomly divide all of her students into two groups. She can grade the homework for one group but not the other. All homework would be returned to the students. The teacher could then compare test scores of each of the groups.
500
This is the value of sec x if
tan theta =-4/3and pi/2<theta<pi
What is
-5/3