Statistics

Which of the following is NOT a characteristic of t-distribution?

• Like the normal distribution, the t-distribution has a smooth shape.

• Like the normal distribution, the t-distribution is symmetric. If you think about folding it in half at the mean, each side will be the same.

• Like a standard normal distribution (or z-distribution), the t-distribution has a mean of one.

• The normal distribution assumes that the population standard deviation is known. The t-distribution does not make this assumption.

It refers to the entire group that is under study or investigation.

• population

• sample

• random sampling

• subset

Which of the following must be used as the significance level if we want a lower possibility of correct decision?

• 1%

• 2%

• 5%

• 10%

When is a Type II error committed?

• We reject a null hypothesis that is true.

• We fail to reject a null hypothesis that is true.

• We reject a null hypothesis that is false.

• We fail to reject a null hypothesis that is false.

In a one-tailed test, in which critical values below will the computed z of 2.312 falls in the non-rejection region?

• 1.383

• 1.533

• 2.228

• 2.354

This refers to the measure of position with data divided into 100 parts.

• Percentiles

• Quartiles

• Deciles

• Median

Andrew knows that through education, he can achieve his dreams. That is why to support his schooling, Andrew is doing a part-time job. For each hour of working, he earns Php40. What is the independent variable?

• Php 40

• part-time job

• amount earned

• hours spent in doing part-time job

What is the right-tailed area if the confidence interval is 75%?

• 0.05

• 0.10

• 0.005

• 0.25

In a study done on the life expectancy of 500 people in a certain geographic region, the mean age at death was 72 years and the standard deviation was 5.3 years. If a sample of 50 people from this region is selected, and the probability that the mean life expectancy will be less than 70 years, which of the following will you use?

• Normal Distribution

• Discrete Probability Distribution

• Central Limit Theorem

• Binomial Distribution

The mean and standard deviation of a population are 200 and 20, respectively. What is the probability of selecting 25 data values with a mean less than 190? A. 69% B. 31% C. 0.6% D. 99%

• 69%

• 31%

• 0.6%

• 99%