Statistics and Probability Answers

 Un inversionista considera la posibilidad de adquirir una tienda de regalos en una terminal de autobuses foráneos y desea estimar el promedio de ventas por cliente, con base en otras tiendas similares que ya posee, estima que la desviación estándar de las ventas por cliente es de $15. ¿Cuál es el tamaño mínimo de la muestra aleatoria que debe tomar para hacer la estimación si desea un nivel de confianza de90% y un margen de error no mayor que $1?

I need the process

Jenni is eating a package of gunny bears. There are 4 red, 2 yellow and 3 green gummy bears left. what is the probability of her selecting a red gummy beat, eating it then selecting a green gummy bear?

 A chord connecting two points randomly chosen on a circunference of a disk of radius 1 cuts it into two segments. Select the best approximation to the mathematical expectation of the area of the smaller segment.

1. O.2

2. 0.6

3. 0.4

4 0. 8

5. 1

A box contains 500 envelopes: 75 of them contain P1,000, 150 envelopes contain P500, and 275 of them contain P100. You are asked to choose one envelope from the box. What is the probability that the envelope you have chosen is less than P1,000?

The IQ’s of the college students are known to be normally distributed with mean

of 123. A random sample of 49 students showed an average of IQ 120.67 and

standard deviation 8.44. Test the hypothesis that μ=123 against the alternative that

it is less. Let α=0.05.

11. The following shows the age distribution in years of 40 youths at a youth rally.

Age in years (x)

Frequency (f)

7 − 12. 4

12 − 17

17 − 22. 15

22 − 27

27 − 32. 5

Total. 40

Given that the median age is 19.8 years:

i.

Find the missing frequencies to the nearest whole number.

ii.

Find the mode of this distribution.

iii.

How many youths are older than 17 years?

iv.

Include a column for relative frequencies.

v.

Hence, or otherwise, construct a pie chart for this data.

random sample of size 4 from a finite population of 3,6,9

A random sample of size 4 is taken with replacement from a population with population mean of 12 and population variance of 8. What is the variance of the sampling distribution.

A random sample of size 4 is taken with replacement from a population with population mean of 12 and population variance of 8. What is the mean of the sampling distribution. 

A random variable is uniformly distributed between 100 and 150. a. Draw the density function. b. Find P(X > 110). c. Find P(120 < X < 135). d. Find P(X < 122).