Question

In a particular retail clothing store, approximately 25% of potential customers who walk into the store make a purchase. In a random sample of 20 customers that walked into the store, ________________________________________ a. what is the probability that exactly 10 of the customers make purchases? b. what is the probability that at least 2 of the customers make purchases? c. how many of the customers are expected to make purchases? d. what is the standard deviation of the number of customers who make purchases?

271

likes
1353 views

Answer to a math question In a particular retail clothing store, approximately 25% of potential customers who walk into the store make a purchase. In a random sample of 20 customers that walked into the store, ________________________________________ a. what is the probability that exactly 10 of the customers make purchases? b. what is the probability that at least 2 of the customers make purchases? c. how many of the customers are expected to make purchases? d. what is the standard deviation of the number of customers who make purchases?

Expert avatar
Andrea
4.5
86 Answers
Let's denote the probability of a customer making a purchase as p = 0.25 and the number of trials as n = 20 .

a. To find the probability that exactly 10 customers make purchases in a sample of 20, we can use the binomial probability formula:
P(X = k) = \binom{n}{k} \cdot p^k \cdot (1-p)^{n-k}

Substitute k = 10 , n = 20 , and p = 0.25 into the formula:
P(X = 10) = \binom{20}{10} \cdot (0.25)^{10} \cdot (0.75)^{10}

Calculating this gives:
P(X=10)=\binom{20}{10}\cdot(0.25)^{10}\cdot(0.75)^{10}\approx0.0099



Frequently asked questions (FAQs)
Math question: What is the value of x in the equation log₂(x) + log₂(2) = 3?
+
What is the circumference of a circle with a radius of 5 cm?
+
What is the resultant vector when two vectors, 𝐴 = (3, 2) and 𝐵 = (-4, 5), are multiplied together?
+
New questions in Mathematics
A normal random variable x has a mean of 50 and a standard deviation of 10. Would it be unusual to see the value x = 0? Explain your answer.
Let f(x)=||x|−6|+|15−|x|| . Then f(6)+f(15) is equal to:
The ratio of tomatoes to red apples is 2:5. If there are 20 tomaoes in the garden, how many red apples are there?
Determine the absolute extrema of the function 𝑓(𝑥)=𝑥3−18𝑥2 96𝑥 , on the interval [1,10]
Divide 22 by 5 solve it by array and an area model
-4y-6(2z-4y)-6
Pedro had 80% of the amount needed to buy a game. Of this amount, you spent 15% on a watch and therefore, you will need to add another R$640.00 to purchase this game. Is the value of the game?
Your boss asks you to plan the sample size for a randomized, double-blind, controlled trial in the clinical development of a cure for irritable bowl disease. Current standard treatment shall be compared with a new treatment in this trial. The S3-guideline of AWM demonstrated a mean change of the summary score of the validated health related quality of life questionnaire at 8 weeks of 16 with standard deviation 23 under standard treatment. You quote the drop-out rate of 11% from literature (previous phase of clinical development). Your research yielded a clinically important effect of 4 that has been found to be the Minimal Clinically Important Difference (MCID). In order to demonstrate superiority of the new treatment over standard of care, you assume that the change in of the summary score of the validated health related quality of life questionnaire follows a normal distribution, and that the standard deviation is the same for both treatments. How many patientes would one need to recruit for the trial to demonstrate the clinically interesting difference between treatments at significance level 5% with 95% power?
Let A, B, C and D be sets such that | A| = |C| and |B| = |D|. Prove that |A × B| = |C × D|
Quadratic equation 2X = 15/X + 7
The probability of growing a seedling from a seed is 0.62. How many seeds do I need to plant so that the probability of growing at least one seedling is greater than or equal to 0.87?
A company made 150,000 in the first year 145,000 in the second 140,000 in the third year successively during the first decade of this company's existence it made a total of
A 20,000 kg school bus is moving at 30 km per hour on a straight road. At that moment, it applies the brakes until it comes to a complete stop after 15 seconds. Calculate the acceleration and the force acting on the body.
Solve for B write your answer as a fraction or as a whole number. B-1/7=4
simplify w+[6+(-5)]
For how long does the principal amount of €7,537 bring the same interest as the principal amount of €12,345 invested for 8 months? Interest calculation is simple and decursive.
Arturo had hospitalization expenses of $8,300. Your policy for medical expenses Seniors have a deductible of $500 and expenses are paid at a 20% coinsurance. These are the first expenses ever this year, how much will Arturo have to pay in your bill for hospitalization expenses?
7-1=6 6x2=12 Explain that
2p-6=8+5(p+9)
To apply a diagnostic test, in how many ways can 14 students be chosen out of 25? if the order does not matter