Homework Answers

Fifteen pupils from school B have mean IQ of 110 and a variance of 64, while 20 pupils from school C show a mean IQ of 114 and a variance of 78. What is the z-computed value?

A rectangular gutter is formed by bending a 24 cm wide sheet of metal as shown. As a whole number, what is the height of a the gutter of maximum capacity?

Given the population 1,2,3,5,7,11 and 13 compute the following.

A.population of mean

B.Population of variance

C.population standard deviation

1) The researcher wants to estimate the number of hours that 5-year old children spend watching television. A sample of 50 five-year old children was observed to have a mean viewing time of 3 hours. The population is normally distributed with a population standard deviation 0.5 hour, find:

a) the best point estimate of the population mean.

b) the 90% confidence interval of the population mean.

2) The mean scores of a random sample of 17 students who took a special test is 83.5. If the sd of the scores is 4.1, the sample comes from an approximately normal population, find the point and interval estimates of the population mean adopting a confidence level of 95%.

3) In a gymnasium, physical exercise has a mean length of 30 mins with a sd of 6 mins. A PE major wants to estimate the true length of the exercise with a maximum error pegged at 0.5 adopting the 95% confidence interval. How many respondents does he need?

Find equivalent functional definition for each of the following and draw a graph of the function.

f(x) = |x|•|x-1|

Find the equivalent acute angle of 13.5

Find the equivalent functional definition for each of the following and draw a graph of the function.

f(x)= x+|x|.

Find equivalent functional definition for each of the following and draw a graph of a function.

f(x)=2x -|x| + |x-1|

Prove that |a+b| - |a-b| ≤ 2|b|.