Statistics - math word problems

Number of problems found: 251

The test
The test contains four questions, and there are five different answers to each of them, of which only one is correct, the others are incorrect. What is the probability that a student who does not know the answer to any question will guess the right answer
Troops
There are two leaders in the tourist group, with an average age of 30 years and several children with an average age of 10 years. The total age of the group is 12 years. How many children are in the group?
All use computer
It is reported that 72% of working women use computers at work. Choose 3 women at random, find the probability that all 3 women use a computer in their jobs.
Father and sons
Father is 27 and his sons 2 and one year. In how many years will his sons sum up to half his age?
Large family
The average age of all family members (children, mother, father, grandmother, grandfather) is 29 years. The average age of parents is 40 years, grandparents 66 years and all children are 5 years. How many children are there in this family?
Average price
Sixth grade went on a trip to Moravia. Each of the 26 pupils paid CZK 320 and the school paid a total of CZK 3,510. What was the average price of a trip per student?
Beer tapping
When checking compliance with the beer tapping, it was found that 60% of the offered beers were underfilled. The others were fine. Thus, instead of 0.5 l, the volume was 4.4 dcl on average. What was the volume of one average underfilled beer?
My father
My father cut 78 slats on the fence. The shortest of them was 97 cm long, the longer one was 102 cm long. What was the total length of the slats in cm?
Four pavers
Four pavers would pave the square in 18 days. How many pavers do you need to add to done work in 12 days?
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?
Midpoint 6
FM=8a+1, FG=42, a=? Point M is the midpoint of FG. Find unknown a.
Aircraft angines
The two engines of the aircraft are enough to supply the fuel for five hours of operation. However, one of the engines has a malfunction and thus consumes one-third more fuel. How long can the plane be in the air before it runs out of fuel? After an hour
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%.
Trees avg
The worker planted 96 trees on Monday, 120 on Tuesday and 61 trees on Wednesday. How many trees did he plant on Thursday if he averaged 105 trees per day?
Test scores
Jo's test scores on the first four 100 point exams are as follows: 96,90,76, and 88. If all exams are worth the same percent, what is the minimum test score necessary on his last exam to earn an A grade in the class (90% or better)?
Average temperature
The average temperature from Monday to Sunday was 40.5°F and the average temperature from Monday to Saturday was 42.8°F. What was the temperature on Sunday?
Lifespan
The lifetime of a light bulb is a random variable with a normal distribution of x = 300 hours, σ = 35 hours. a) What is the probability that a randomly selected light bulb will have a lifespan of more than 320 hours? b) Up to what value of L hours can the
Six questions test
There are six questions in the test. There are 3 answers to each - only one is correct. In order for a student to take the exam, at least four questions must be answered correctly. Alan didn't learn at all, so he circled the answers only by guessing. What
Coordinates of a centroind
Let’s A = [3, 2, 0], B = [1, -2, 4] and C = [1, 1, 1] be 3 points in space. Calculate the coordinates of the centroid of △ABC (the intersection of the medians).
Probability of malaria
A survey carried out at a certain hospital indicates that the probability that a patient tested positive for malaria is 0.6. What is the probability that two patients selected at random (i) one is negative while the other tested positive? (i) both patient