6.2
Eric reads an article that says 15 out of 25 adults use their computer every day. He collects data from a random sample of adults. Out of 1,270 adults, estimate the number of adults who use their computer every day.
About 762
Mr. Herman compared the student scores for two class periods on a social studies final.
The median test score of Period 2 is _____ the median test score of Period 1.
Less than
Scott compared the wait times at the two local amusement parks, RidesRUs and AdventureWorld. At RidesRUs, the range in wait times is 15 minutes and the IQR is 10 minutes. At AdventureWorld, the range in wait times is 30 minutes and the IQR is 18 minutes.
What might you conclude about the wait times at each amusement park based on the ranges and interquartile ranges? (are they more or less consistent somewhere?)
The wait times at RidesRUs are more consistent than the wait times at AdventureWorld.
A teacher collects data about test scores on a recent math test from two classes. The teacher calculates the median and the interquartile range (IQR) for each data set.
Which class had higher test scores and how do you know?
Class one typically has higher test scores based on the mean. (75 is higher than 70)
Wade and Riley ride their bikes to school each morning. They want to compare who takes the longest time to ride their bike to school throughout the week.
Is the data numerical or categorical?
Numerical
A random selection will be made from a bag containing different colored disks. Of the 25 disks in the bag, 5 are yellow.
The probability that a yellow disk will be selected is ______
1 out of 5
Ellen flipped a coin 80 times. The coin landed heads up 44 times and tails up 36 times. Find the experimental probability of the coin landing tails up.
45%
Data were collected from a random sample of 18 teens at the mall. It was found that 16 of those teens owned bicycles. If there are 504 teens at the mall, how many can you estimate own a bicycles?
448
Mr. Herman can conclude that the test scores were generally higher in _______
He also can conclude that the test scores were more consistent in ________
Period 1, Period 2
The measure of variability that best describes the data is the _____
Range
Angela is comparing the amounts of rainfall over the past month in two cities on days when it rained. In City 1, the range in rainfall is 4.5 centimeters and the IQR is 1.5 centimeters. In City 2, the range is 5 centimeters and the IQR is 3 centimeters. What might you conclude about the cities based on the ranges and interquartile ranges?
Rainfall amounts on days it rains are more consistent for city 1
Jayna keeps track of the daily low temperatures for November. She wants to find the average low temperature for the month of November.
What type of data display should Jayna use to display the data?
Line Plot/Dot Plot
A random selection will be made from a bag containing different colored disks. Of the 25 disks in the bag, 5 are yellow.
Describe the likelihood of randomly selecting a yellow disk.
It is UNLIKELY.
Adama rolls a die with faces labeled 1 through 10. If he rolls the die 40 times how many times would he expect it to land on a number less than 10?
36 times
The students in Mr. K's class are a representative sample of all the students at the school. His class has 18 boys and 12 girls.
There are 1,700 students in the school. If you pick one student from the school, are you more likely to pick a girl or a boy?
If there are 1,700 students in the school, there are about 1,020 boys and 680 girls. So, you are more likely to pick a boy.
Mr. Mitchell wants to buy new batteries for his remote-controlled cars. He tests two different brands for 5 days and records the number of hours of battery life for each brand. He decides that SuperCHARGED batteries have more consistent battery life.
Which measures of center and variability should be used to compare the performances of each battery brand?
Mean and range - The data are distributed evenly.
The typical number of visits to the library is represented by the _____
Mean
Compare the IQR of the two cities and tell me what they are and whose is greater.
IQR for Kingman = 4
IQR for Barstow = 13
Barstow IQR is greater.
Amy wants to keep a record of how she spends money each month. She decides to display her data in a circle graph. Do you agree a circle graph is an appropriate graph for this data set? Why?
Yes - It's categorical
Michael is planting a garden. The probability that a seed will produce a plant is 9/10.
What is the probability as a percent that a seed will produce a plant and what is the likelihood that a seed will produce a plant?
90% and likely
Tonya flips a fair coin and records the number of times it lands on heads. The coin lands on heads 36 of the first 50 trials. The coin lands on heads 58 of the first 100 trials. Compare the experimental probability to the theoretical probability after 50 trials and 100 trials.
What is the theoretical probability?
1/2 or 0.50 or 50%
Did Mr. Mitchell choose the right brand of battery?
Yes! The range of battery life for SuperCHARGED is less than the range for LongLasting.
How do you find range?
Maximum - Minimum
What does the mean describe in the data set? (AKA How do you find it and what is it)
The mean of the data set is the sum of the heights divided by the number of flowers: the average flower height is about 3.08 inches.
Miguel collected data on different shoe types owned. He wants to compare the different shoe types to each other and to the total number of shoes owned.
Categorical or numerical?
Categorical
A jar has 20 marbles: 6 black, 4 brown, 8 white, and 2 blue. Julie draws a marble from the jar.
What is the sample space?
S = {black, black, black, black, black, black, brown, brown, brown, brown, white, white, white, white, white, white, white, white, blue, blue}
Mel has a bag of 8 marbles: 2 red, 3 yellow, and 3 green. She draws a marble from the bag, writes down the color, replaces it, and draws again. She repeats this process for 40 trials and records drawing a yellow marble 12 times.
After 40 trials, what is the experimental probability of drawing a yellow marble?
After 40 trials, the experimental probability is 12/40 = 0.30 or 30%.
City A newspaper had 2,925 subscriptions last month and 975 of those were on-line subscriptions.
City A newspaper plans to have 57,000 subscriptions this year. Predict approximately how many of those subscriptions will be on-line.
Approximately 19,000 of the subscriptions will be online.
The line plots show the numbers of hours piano students practiced in a week for two grades. Which grade has more consistent piano practice times?
The students in the 7th grade had more consistent times because the range of the 7th-grade data is 3 hours, which is less than 5 hours, the range of 8th-grade data.
How do you find IQR?
Upper Quartile - Lower Quartile
What does the range describe in the data set? AKA How do find it and what is it?
The range describes the difference between the greatest and the least heights of flowers, which is 2.9 inches
What type of graph would you use to display high temperature data on specific days of the week.
Bar Chart
A number solid with faces labeled 1 through 16 is rolled. What is the theoretical probability of rolling a 16 when the number solid is rolled?
Show me formula, fraction, decimal and percent.
P(16) = 1/16 = 0.0625, or 6.25%
Carrie rolls a number cube with 6 faces labeled A, B. C, D, E, and F 100 times. She rolls F eighteen times. How does her experimental probability compare to the theoretical probability?
The experimental probability of 18% is slightly greater than the theoretical probability of 16.7%.