Math Answers

Q life time of led follow exponential distribution with mean life of 5000 burning hours. if one such LED is selected at random from a big lot, what is the probability that it will last for 

1. at least 4000 hours 

2. almost 10000 hours

Also state the standard deviation of the life time distribution. Given e raised to -0.8 is 0.4493 and e raised to -2 is 0.1353

A group of students got the following scores in an achievement test:9,12,15,18,21 and 24 . consider the sample of size 3 that can be drawn from this population. Construct a sampling distribution of the resulting means and find the probability

a bus is moving at 8m/s when passenger walks forward at 1.5m/s relative to the bus . how fast is this passenger moving as seen and measured by (a) a person waiting at the bus stop and (b) the driver of the bus?

Use a truth table to determine whether the given statement is a tautology or self-contradiction.

1. ~[p ∧ ( ~p v q)] v q

2. [p ∧ ( ~p v q)] v q

A quality control engineer knows that a flash drive produced by a company pass the company’s standard 95% of the time. He usually does a random checking of 20 flash drives from the day’s production and approves the whole production when no more than flash drives fail to meet the standards. What is the probability that the quality control engineer accepts the whole production for the day?

The principal claims that the students in his school are above average intelligence. A random sample of 35 IQ scores have a mean score of 110.5. Is there sufficient evidence to support the principal’s claim? The mean population IQ is 100 with a standard deviation of 25. Use =1%.

suppose that no of accident occuring on high way is possion with random vairables lamda=3

Find each of the following percentile points under the normal curve.

1. P90
2. P68
3. P40
4. P32

Find the area between z = -1.35 and z = 2.95?

*

Find the length of arc of the curve 𝑦 = 𝑥 3⁄2 /√3 from (0, 0) to (4, √8 / 3 )