Statistics and Probability Answers

An electric bulb company manufacturing company claims that the bulbs produced by them have a mean life of 1250 hours. A random sample of 25 bulbs gives an average life of 1290 hours with standard deviation of of 110 hours. Use 5% level of significance and test the claim if bulb life follows is 1250 hours. ( t _{0.025 (24) =2.064).}

A particular brand of diet margarine has analysed to determine the level of polyunsaturated fatry acids (in percentages).A sample of six packages resulted in the following data 16.8,17.2,17.2,16.9,16.5,17.1 .Find the 95%confidence interval for the mean level of polyunsaturated fatty accid for this brand of diet margarine

A job interview at a college attracts 100 candidates of which 30% are females and 70% are males. 40% of both female and male candidates have less than 6 months of work experience and the other 60% have at least 6 months of work experience.

If only one of them will be hired, calculate the probability that he/she is a

(i) Male and has less than 6 months of work experience

(ii) Female or has at least 6 months of work experience

1. Teaching a subject requires much more than simply knowledge of that subject. Knowing and deeply understanding the mathematics is crucial, but it is just the beginning.” Critically discuss the above statement giving reasons for your responses. [25]

‘read, interpret and draw simple inferences (conclusions) from tables and statistical diagrams

The above specific objective is stated in the NSSCO syllabi under the topic Statistics and Probability. Discuss how you would you plan to teach this concept, clearly stipulate what happens at every point of the lesson. Also, indicate how you will include and develop local resources in order to enhance learners’ understanding. [50] 

A group of srudents in their research would like to determine the EQ of Mindanao Science State University. They followed the instruction given their research adviser. Through simple random sampling, they got 150 students from a population of 3000 students. Among sampled srudents, the average EQ score is 115 with a standard deviation of 10. What is the sample mean?

Suppose X ~ N(3 , 4). If sample size = 100, P(∑ Xi > 250) = ?. Draw

a figure.

The process of making inference about a population based on information obtiined from a sample

1. The mean scores of a random sample of 17 students who took a special test is 83.5. If the standard deviation of the scores is 4.1, and the sample comes from an approximately normal population, find the interval estimates of the population mean adopting a confidence level of 90%.

ILAW Manufacturing company produces bulbs that last a mean of 900 hours with a standard deviation of 110 hours. what is the probability that the mean lifetime of a random sample of 15 of these bulbs is less than 850 hours?