Instruction: Determine whether the following statements has a known or unknown

population variance and write the complete answer on the second column. Identify also the

formula to be used to estimate the standard error of the mean by writing the symbol

, when the population variance is known and the symbol when the population

variance is unknown.

1. Hereza Start is an enrichment program for Grade 11

SHS students. The program's heads would like to know

the mean intelligence (IQ) of its participants. They know

that IQ has standard deviation of 15 points. They take

a random sample of 20 students and administer IQ

tests. These are the scores:98, 82, 100, 102, 78, 79, 95,

89, 90, 99, 105, 103, 93, 99, 101, 89, 102, 76, 91, 100.

2. Given the following values: = 110, = 6, = 16, =

102, and = 7

3. Joel administered a mathematics achievement test to a

random sample of 40 Grade 10 students. In this

sample, he obtained the mean and variance to 89 and

81 respectively. The population mean is 85.

4. A random sample of 100 school heads were

administered a Management Skills Test. The sample

mean and the variance were 81 and 26.98. In the

standardization test, the mean was 79 and the standard

deviation was 7.

5. A finite population composed of eight items whose

values are 9, 3, 12, 7, 8, 11, 15 and 10. Samples of 4

items are drawn at random without replacement.