Statistics and Probability Answers

In a survey of 300 random households in a particular village, mother's have been asked if they used cellphone to communicate there are 76 who said YES, Use 90%, 95% and 99% confidence to estimate the proportion of all mothers who use the cellphone to communicate

Find the areas of each of the following z-scores

1. 0.50

2. 0.99

3. -2.58

4. 3.16

5. -0.52

6. -0.12

In a high school class, 35% of the students take Spanish as a foreign language, 15% take French as a foreign language, and 40% take at least one of these languages. What is the probability that a randomly chosen student takes French given that the student takes Spanish?

A. The following are the heights of four students in centimeters. Suppose

samples of size 2 are taken from this population of four students.

STUDENTS | HEIGHT(in cm)

Cardo 125

Alyana 120

Joaquin 130

Flora 110

a. Compute the mean of the population

b. Compute the mean of the sampling distribution of the sample means

A random sample of 60 Grade 11 students’ ages is obtained to estimate the mean ages of all Grade 11 students. Suppose the sample mean is 17.3 and the population variance is 18, 

It has been reported that 40% of the adult population participate in computer hobbies during their leisure time. A random sample of 180 adults found that 65 engaged in computer hobbies. at a= 0.01, is there sufficient evidence to conclude that the proportion differs from 40%?

It has been reported that 40% of the adult population participate in computer hobbies during their leisure time. A random sample of 180 adults found that 65 engaged in computer hobbies. at a= 0.01, is there sufficient evidence to conclude that the proportion differs from 40%?

X=842, n=1200, 95% confidence

X=842, n=1200, interval estimate 95%

It is reported that the average number of hours of sleep of a college student during regular school days is 6 hours a day .If 28 college students were randomly selected find the probability that the mean number of hours they sleep during regular school days is longer than 6.8 hours .Assume that the variable is normally distributed with standard deviation of 1.2 hours