DSAT extra practice Ch6 Lv2

The table above shows the gender of students at Happy School and the type of pets they own, assuming each student has at most one pet. If a random sample is taken from the students who own pets, what is the probability of selecting a student who does not own a pet duck?

The probability of getting heads when tossing a biased coin is 0.4. Toss the coin 2 times, what is the probability of getting one heads and one tails?

Statistically, around 50% of Americans aged 18-24 cannot identify the state of New York on a map. Select 3 Americans aged 18-24 randomly, what is the probability that two of them cannot identify the state of New York on a map?

A farmer owns 5,000 pigs. Thirty percent of them are female. Of the male pigs, ten percent of them have athletes’ foot; of the female pigs, twenty percent of them have athletes’ foot. The farmer randomly selects a pig. Given that the pig has athletes’ foot, what is the probability that the pig is female?

In a group of people, 40% have fatty liver, 55% have kidney stones, and 30% have both. If a person is selected at random from this group, what is the probability that he/she also has kidney stones given that he/she has fatty liver?

Fifty students took AP Statistics. The histogram above shows the distribution of their final scores. If their teacher decided to fail students in the bottom 20%, what is the minimum score for passing the course?

The pie chart above shows the nutritional composition of tiramisu made by Happy Dessert Shop. Approximately 4 kcal of energy is provided by 1 g of sugar, 4 kcal by 1 g of protein, and 9 kcal by 1 g of fat. One afternoon, Annabelle consumed a serving of tiramisu weighing 150 g. At least how many calories did she consume?

A teacher of HA2 conducted a survey asking 50 students to identify the two most challenging chapters (required to select 2 options), and the results were depicted in the chart above. If the teacher decides not to test on any chapter where more than 30% of the students find it difficult, how many chapters will not be included in the exam?

Tristan caught 250 Japanese spider crabs and calculated the mean, median, mode, and standard deviation of their weights to be 15, 13, 12, and 6 kg, respectively. If the market price of crabs is their weight (kg) multiplied by 50 plus $150, which of the following statements is incorrect?

Jordan wanted to know the IQ of monkeys, so he caught 15 monkeys and measured their IQs. The median is 75. However, Jordan later found out that of these 15 monkeys, one of them was not a monkey, it was a baboon. So Jordan eliminated its data. If the IQ of the baboon is 90, which of the following statements is true?

Franky teaches 2 classes of HPC. There are 30 students in class A, and their average score is 70; There are 20 students in class B, and their average score is 90. If Franky combines the two classes, what is the new average score?

According to a 1920 regulation by the French government, the standard weight for a baguette should be approximately 250 grams. The owner of a traditional French bakery wants to verify if the baguettes in her bakery meets this standard. She randomly selects 120 baguettes and measures an average weight of 247 grams with a margin of error of 7 grams. Which of the following statements is correct?

In Happy city, there are a total of 800,000 people liable for taxation. The national tax agency randomly sampled 6,000 individuals and found that 35% of them owe taxes. If the margin of error for this sampling is 4%, which of the following values could potentially represent the true number of people owing taxes in the Happy city?

Which of the following statements about margins of error is true?

Eating corn can help us understand our digestion speed. The procedure is as follows: eat some corn in the morning and record the time, maintain normal activities throughout the day without consuming more corn. When corn kernels first appear in the bowel movement, record the time. This way, one can roughly determine their digestion speed. A doctor wanted to understand the relationship between age and digestion time, so she randomly selected 50 normal teenagers for an experiment. The scatterplot below shows the age and digestion time of them. Based on this scatterplot, which of the following conclusions can be drawn?

Ms. Hippo loves eating watermelon but is concerned about her blood sugar getting too high. So, she measures the weight of the watermelon before eating it. Half an hour after eating, she measures her blood sugar (mg/dL). She plotted the results in the scatterplot above. If Ms. Hippo does not want her blood sugar to exceed 180 mg/dL, what is the heaviest watermelon she could eat?

A boutique launched a new durian essential oil and placed advertisements. The manager wants to know if the advertising is effective, so she recorded the monthly advertising expenses (in thousands) and the sales revenue (in thousands) from customers who bought the durian essential oil due to the advertisements over the past two years and plotted them on a scatter plot. Which of the following statements is correct?

A motorcycle oil factory has developed a formula that can greatly extend the life of the oil. To test its effectiveness, the manager randomly selected 35 employees and had them change to the new oil before riding as usual. One month later, the TAN value (a measurement of the oil’s condition) of the oil was tested. The chart above shows the test results. The dashed line in the chart is the regression line. If the TAN value of the oil exceeds 3, it should be changed. Customers should change oil after how many kilometers? Round to the nearest integer.

Air quality index and sewage treatment rate are two important environmental indicators of a city. The chart above shows the air quality and sewage treatment rate of 20 cities in the Kingdom of Happiness. The straight line in the chart is the regression line. Which of the following equations is most likely to be the equation of the line?

Let [math]X[/math] and [math]Y[/math] be two variables. If the regression line of [math]X[/math] and [math]Y[/math] is [math]y=0.04x+0.5[/math], which of the following statements is true?

Mr. Rooster wants to raise a Burmese python. To provide a suitable environment, he wants to understand the relationship between the age [math]x[/math] and length [math]y[/math] of a Burmese python. Therefore, he randomly selected 25 Burmese pythons from a biological research institute for measurement. The chart above shows the measurement results. Which of the following equations is most likely the regression line equation for this data?

A businessman wants to hire a Youtuber to help promote his products. To calculate the cost, he randomly contacted 30 Youtubers and asked about their number of subscribers and the probability of successfully selling products. The chart above shows the sampled results. Later, the businessman asked a Youtuber with 500 subscribers to help sell 200 items. If 30 items were sold, how does the Youtuber’s actual success rate compare to the estimated success rate?