Statistics and Probability Answers

A continuous random variable X is normally distributed with a mean of 45 and a standard deviation of 6. Illustrate a normal curve and find the probability of the following:

25-28 (4pts).  P(39 < X < 51)

29-32 (4pts).  P(33 < X < 63)

33-36 (4pts).  P(X > 45)

The scores in the summative test of 11-ABM A are normally distributed with a mean of 65 and a standard deviation of 12. Illustrate a normal curve and find the probability that some students got a score below 40. (Show your solution)

The area between z=0 and z=2.86

Consider a population consisting of 4, 7, 8, 13, and 18. Suppose samples of size 2 are drawn from this population. Find the Population Mean

Below is a class distribution table for the weights(in kg) of athletes who registered for a wrestling competition.

Weight Frequency

70-74 4

75-79 7

80-84 11

85-89 8

Find the mean weight of the wrestlers who will be competing in the tournament. Write your complete solution below

How many possible samples does it have when a population consist of 12 and you have to get a sample size of 4 from it. *

Compute for the mean, the median, and the mode of each set of ungrouped data. Write your answer on the table below.

1.) 12, 31, 29, 6, 10, 8, 13, 27, 24, 16

2.) 52, 52, 52, 50, 55, 50, 57, 49, 60, 49, 62

3.) 35, 42, 36, 40, 49, 33, 39, 37, 44, 28, 43

4.) 62, 49, 60, 49, 57, 50, 55, 50, 52, 52, 52

5.) 11, 30, 28, 5, 9, 7, 12, 26, 23, 15

John's commute from home to work is normally distributed with mean 45 minutes, deviation

standard 3 minutes.

a) What is the probability that John travels from home to work in 30 to 40 minutes?

b) If the starting time at the company is 9:00 am, what time should John start going from home?

so that the probability of getting to work on time is 95%?

Consider a small unit of a factory where there are 5 employees : a supervisor and four labourers. The workers earn a salary of Rs. 5,000 per month each while the supervisor gets Rs. 15,000 per month. Calculate the mean, median and mode of the salaries.

Given x ̅ = 60, s = 8.Find the z-score value of raw score 78 up to two decimal places