Mean + probability - practice problems
Number of problems found: 48
- The usage
The battery usage time installed in a particular smartphone has a Normal distribution with a mean of 25.2 hours and a standard deviation of 7.5 hours. What is the probability of usage time greater than 32? - Q10 - investigate
A nutritionist who investigates fruits reported that the average weight of a raspberry is 4.4 g with a standard deviation of 1.28 g. What is the probability that a randomly selected raspberry would weigh less than 3.1 grams? Let X represent the weight of - Family survey
A total of 160 families with 4 children each were surveyed with the following results. Boys; 4; 3; 2; 1; 0 Girls ; 0; 1; 2; 3; 4 Families; 7; 50; 55; 32; 16 Let the probability of picking a boy or a girl be 1/2. Let P=boy, Q=girl. What is the probability - Bulb life
Tests show that the lives of light bulbs are normally distributed with a mean of 750 hours and a standard deviation of 75 hours. Find the probability that a randomly selected light bulb will last between 675 and 900 hours. - A fair 2
A fair die is thrown two times. What is the probability that the sum of the score is almost 8? - 3 sigma
Students' performance scores in a statistic test have a mean of 70 and a standard deviation of 4.0. The scores obtained can be modeled by a normal distribution. Find the probability that the score of a randomly selected student is i. more than 80 marks ii - The profit 3
An investment's profit (or loss) is normally distributed with a mean of $11,200 and a standard deviation of $8,250. What is the probability of a loss rather than a profit? - Distribution 82042
Assume that the IQ in the population follows a normal distribution with a mean of 100 points and a standard deviation of 10 points. With what probability among 15 randomly selected people: a. Is there anyone with an IQ above 130 points? b. Are there at le - The average 7
The average lifespan for cricket is 90 days, with a standard deviation of 13 days. If we assume that the lifespan of cricket is normally distributed, a. What is the probability a randomly selected cricket has a lifespan of fewer than 75 days? b. What is t - An insurance
An insurance company receives, on average, two claims per week from a particular factory. Assuming that a Poisson distribution can model the number of claims, find the probability it receives. three claims in a given week, more than four claims in a given - Z-score test
The fish weights in a certain lake are normally distributed with a mean of 11 lb and a standard deviation of 6. If four fish are randomly selected, what is the probability that the mean weight will be between 8.6 and 14.6 lb? Your answer should be a decim - The following
The following data represents the number of cases of coffee or filters sold by four sales reps in a recent sales competition. Sales Person; Gourmet; Single Cup; Filters; Total Connor; 142; 325; 30; 497 Paige ; 42; 125; 40; 207 Bryce ; 9; 100; 10; 119 Mall - Distribution 73724
The distribution of the random variable X is given in the following table. Calculate P[X is odd], E[X] and P[1<X≤6] Probability distribution table: xi; 1; 2; 3 ; 4; 5; 6; 7; 8; 9 pi; 0.30; 0.12; 0.18; 0.10; 0.07; 0.07; 0.06; 0.05; 0.05 - Suppose 6
Suppose the life span of a revolutionary light bulb is normally distributed with a mean life span of 70 thousand hours and a standard deviation of 3 thousand hours. If a light bulb is chosen at random: a) what is the probability the life span will be with - The probability
The probability that a life bulb will have a lifetime of more than 682 hours is 0.9788. The probability that a bulb will have a lifetime of more than 703 hours is 0.0051. Find the probability that a bulb will last for more than 648 hours. - Students 34
Students were surveyed as part of a Statistics project to determine if younger adults are more likely to have tattoos. The results are listed in the two-way table below: age; At least one tattoo; No tattoo; Row totals Age 18 - 29; 165 ; 342; 507 Age 30 - - An exam - normal distribution
Five thousand students take an exam with a mean of 59 and a deviation of 8. How many students will score less than 75? - Three sigma rule
Stomach weights are normally distributed, with a mean of 1314g and a standard deviation of 113g. State the probability that a randomly selected stomach weighs more than 1118g. (Report the probabilities using at least four decimal places. ) - Probability 64174
The banker deals, on average, with five clients a day. Find the probability that the number of clients (in one day) will be greater than 4. - Population variance
In a California community college, 60% of students will transfer to a college in the CSU system. The number of students in a sample who will transfer follows a binomial distribution. If eight students are randomly selected, find the population variance σ²
Do you have homework that you need help solving? Ask a question, and we will try to solve it.