Sophia Statistics Final Milestone WITH correct answers

Sophia Statistics Final Milestone Score 21/25 This chart shows the number of students of different age groups who participated in a quiz. Which of the following statements about the stack plot is true? RATIONALE If we note that the greatest area for the girls is the longest darker region, this occurs in the age group 17-19. CONCEPT Stack Plots I need help with this question 2 Jay wants to study nutrition and performance in schools using available data. Which of the scenarios below will provide Jay with available data? RATIONALE Recall, for data to be considered available data it must already be collected. Since the grades data and survey data were already collected these are examples of available data. CONCEPT Data I need help with this question 3 Regan wants to study how reading on a computer affects comprehension among elementary school students. Regan thinks that girls and boys might differ and he also suspects that grade level will affect the results. He decides to create a male and a female group for each grade. Within each group, he randomly assigns half of the students to read an article on paper and half of the students to read the article on a computer. Which type of experimental design does this situation illustrate? RATIONALE Since students are put into gender and grade blocks and are then assigned treatment or control randomly this is called a randomized block design. CONCEPT Randomized Block Design I need help with this question 4 RATIONALE The defining part of experimental setting is that the researcher can control the setting and apply some treatment to observe how it affects an outcome of interest. CONCEPT Observational Studies and Experiments I need help with this question 5 Rachel measured the lengths of a random sample of 100 screws. The mean length was 2.9 inches, and the population standard deviation is 0.1 inch. To see if the batch of screws has a significantly different mean length from 3 inches, what would the value of the z-test statistic be? -1 RATIONALE If we first note the denominator of Then, getting the z-score we can note it is This tells us that 2.9 is 10 standard deviations below the value of 3, which is extremely far away. CONCEPT Z-Test for Population Means I need help with this question 6 Jesse takes two data points from the weight and feed cost data set to calculate a slope, or average rate of change. A ferret weighs 2.1 pounds and costs $3.40 per week to feed, while a Labrador Retriever weighs 70 pounds and costs $7.50 per week to feed. Using weight as the explanatory variable, what is the slope of the line between these two points? Answer choices are rounded to the nearest hundredth. RATIONALE In order to get slope, we can use the formula: s l o p e equals fraction numerator y 2 minus y 1 over denominator x 2 minus x 1 end fraction. Using the information provided, the two points are: (2.1 lb., $3.40) and (70 lb., $7.50). We can note that: CONCEPT Linear Equation Algebra Review I need help with this question 7 Eric is randomly drawing cards from a deck of 52. He first draws a red card, places it back in the deck, shuffles the deck, and then draws another card. What is the probability of drawing a red card, placing it back in the deck, and drawing another red card? Answer choices are in the form of a percentage, rounded to the nearest whole number. RATIONALE Since Eric puts the card back and re-shuffles, the two events (first draw and second draw) are independent of each other. To find the probability of red on the first draw and second draw, we can use the following formula: Note that the probability of drawing a red card is or for each event. CONCEPT "And" Probability for Independent Events I need help with this question 8 A travel agency contacted a department store and obtained the list of all people who made purchases using their credit cards at the store in the last month. The agency then surveyed a random sample from the list, calling them to ask their preference for air travel or train travel for taking holidays. Which of the following types of bias affects the conclusions of the survey? RATIONALE Selection bias is when the mode of selection introduces a bias in the sample so that it is not representative of the population of interest. Since they only collected information from those using their credit card at a department store, this does not represent how people travel in general and is therefore an example of selection bias. CONCEPT Selection and Deliberate Bias I need help with this question 9 Jenae is able to purchase a different brand of coffee for half the price from a new supplier. She anticipated that her co-workers would object to switching to the new brand, as they were really partial to the coffee they have been drinking so far. Indeed, when offered a taste test of the old brand versus the new brand, her co-workers unanimously rejected the new brand. Jenae's boss, Steven, pointed out that this result was most likely due to the fact that the taste test was not . RATIONALE Since they didn't keep the participants unaware of what brand they were tasting, this could influence the findings. So, the rejection of the new brand was likely due to not blinding them from what brand they were drinking. CONCEPT Blinding I need help with this question 10 Fred Anderson, an artist, has recorded the number of visitors who visited his exhibit in the first 8 hours of opening day. He has made a scatter plot to depict the relationship between the number of hours and the number of visitors. How many visitors were there during the fourth hour? RATIONALE The number of visitors at 4 hours is 4 visitors. This is the value that is directly at the value at 4 on the horizontal axis. CONCEPT Scatterplot I need help with this question 11 The third quartile (Q3) value from this box plot is . RATIONALE The value for Q3 is the right edge of the box, which in this figure is 48. CONCEPT Five Number Summary and Boxplots I need help with this question 12 Shawna reads a scatterplot that displays the relationship between the number of cars owned per household and the average number of citizens who have health insurance in neighborhoods across the country. The plot shows a strong positive correlation. Shawna recalls that correlation does not imply causation. In this example, Shawna sees that increasing the number of cars per household would not cause members of her community to purchase health insurance. Identify the lurking variable that is causing an increase in both the number of cars owned and the average number of citizens with health insurance. RATIONALE Recall that a lurking variable is something that must be related to the outcome and explanatory variable that when considered can help explain a relationship between 2 variables. Since higher income is positively related to owning more cars and having health insurance, this variable would help explain why we see this association. CONCEPT Correlation and Causation I need help with this question 13 Select the statement that correctly describes a Type I error. is rejected when it is actually false. RATIONALE Recall a Type I error is when we incorrectly reject a true null hypothesis. So we would reject using sample evidence, when in fact it was not true. CONCEPT Type I/II Errors I need help with this question 14 Select the following statement that describes o verlapping events. ……………………………………………CONTINUED……………………………………………..