Weighted average - practice problems
Number of problems found: 44
- Average score
In a math exam, two students scored 95, six students scored 90, 3 students scored 80, and one students scored 50. What was the average score for the class?
- Day trip
A group of tourists went on a day trip. For two hours they walked at a speed of 6 km/h, for another hour they climbed a steep hill at a speed of 2 km/h, spent an hour and a half at lunch, then in an hour they inspected the castle garden at a free step at
- Unemployment rate
Over the last 16 years, the country's unemployment rate has changed according to the following frequency table: years of unemployment: 2 5 2 3 3 1 unemployment rate: 0.5 1 1.5 2 2.5 3 in % (percent). Determine the two-sided confidence interval for the var
The meadow was divided into 30 equally large parts and then it was calculated how many seedlings are in each part. It was found that there were no seedlings in six parts, five parts contained one seedling, twelve parts two seedlings and seven parts three
There is 5 l of water with a temperature of 20°C in the bucket. We add 3 liters of hot water. The resulting temperature will be 30°C. What was the temperature of the hot water?
- Frequency distribution
The following frequency distribution gives the time spent for fill-up at a gas station. Assume that each value in a class is equal to the midpoint of the class. Estimate the mean fill-up time for the given data. Round your answer to the nearest hundred
- CoG center
Find the position of the center of gravity of a system of four mass points having masses, m1, m2 = 2 m1, m3 = 3 m1, and m4 = 4 m1, if they lie at the vertices of an isosceles tetrahedron. (in all case
The pharmacist had a 12 l vessel herbal lotion, which contained a 30% active ingredient. Her assistant poured 18 liters of herbal lotion containing 45% of the active ingredient into a container. What percentage of herbal lotion was produced?
- Weighted harmonic average
Ten workers will do some work in 2 minutes, five workers in 10 minutes, and three workers in 6 minutes. How many minutes per average worker per worker?
- Three groups
In the company, employees are divided into three groups. In the first group, which includes 12% of the company's total number of employees, the average salary is CZK 40,000, in the second group CZK 35,000, in the third group CZK 25,000. The average salary
The table is given: days complaints 0-4 2 5-9 4 10-14 8 15-19 6 20-24 4 25-29 3 30-34 3 1.1 What percentage of complaints were resolved within 2weeks? 1.2 calculate the mean number of days to resolve these complaints. 1.3 calculate the modal number of day
- Company car
Ms. Vaňková has a company car equipped with a multifunction indicator, on which she can monitor the average petrol consumption during individual rides. During the first ride, mostly in city traffic, it traveled 20.5 km, with an average consumption of 7.8L
- City market
Apples were sold at contractual prices at the city market. Calculate the average price of 1 kg of apples sold: Stand, Sale kg, Price CZK/kg 1 325 6.20 2 194 7.00 3 258 6.50 4 870 5.90 5 275 6.40
- Water mixing
We have 520 ml of hot water and 640 ml of water at 48°C. What is the temperature of approximately hot water when the resulting mixture has a temperature of 65°C?
- Average height
There are twice as many girls in the class as there are boys. The average height of girls is 177 cm, boys 186 cm. What is the average height of students in this class?
- Corona virus
Calculate an estimate of the percentage of GDP (Gross Domestic Product) declined due to the quarantine related to the corona COVID-19 virus that lasts for 2 months, during which time the economic activity is down by 80%.
- Mixture of nuts
The mixture of nuts should be prepared from almonds, peanuts and cashew nuts ratio 1: 2: 3 (respectively). The price of almonds is 150 CZK/kg, the price of peanuts is 140 CZK/kg and the price of cashew nuts is 180 CZK/kg. The price of the mixture is deter
- The triangle
The triangle is given by three vertices: A [0.0] B [-4.2] C [-6.0] Calculate V (intersection of heights), T (center of gravity), O - center of a circle circumscribed
- Between two bus stops
Wanda lives between two bus stops at three-eighths of their distance. He started the house today and found that he would have arrived at the bus stop if he was running to one or the other stop. The average bus speed is 60 km/h. What is the average speed o
- Centroid - two bodies
A body is composed of a 0.8 m long bar and a sphere with a radius of 0.1m attached so that its center lies on the longitudinal axis of the bar. Both bodies are of the same uniform material. The sphere is twice as heavy as the bar. Find the center of gravi