Statistics and Probability Answers

4. Sam has 6 rose bushes. He counted the flowers on each of them. There are 82,5 4, 11 and 9. Find the Standard Deviation. X a "Usualnumber of flowers? X is your last two digits of your CUNYFirst ID Number. (00=0,01=1,...)(20 points)

the leader of association of jeepney drivers claims that the average daily take home pay of all jeepney drivers in pasay city is php 400. a random sample of 100 jeepney drivers in pasay city was interviewed and the average daily take home pay of these drivers is found to be php 425.use a 0.05 significance level to find out if the average daily take home pay of all jeepney drivers in pasay city is different from php 400. assume that the population variance is php8464.

According to last year's report, a Filipino household spends an average of Php400 per day for food. Suppose you recently took random samples of 25 households. You determined how much each household spent for food each day and the results revealed a mean of Php390 and a standard deviation of Php21.50. Using a 0.01 level of significance, can it be concluded that the average amount spent per day for food of a Filipino household has decreased? Assume normality over the population.

The Head of the Math Department announced that the mean score of Grade 9 students in the first periodic examination in Mathematics was 89 and the standard deviation was 12. One student, who believed that the mean score was less than this, randomly selected 34 students and computed their mean score. She obtained a mean score of 85. At 0.01 level of significance, test the student's belief.

On average, a painter misses 5 spots per room while painting houses. Write your answers to three decimal places.

What is the probability that in the next room he:

A) will forget to paint a maximum of 4 spots?

B) will forget no spots?

C) Find the mean of the number of unpainted spots in a house of 7 rooms.

A travel agency had 2 cars which it hires daily. The number of demands for a car on each

day is distributed as a Poisson cariate with mean 1.5. Find the probability that on a particular

day (i) there was no demand (ii) a demand is refused?

A switch board can handle only 4 telephone calls per minute. If the incoming calls per

minute follow poission distribution with parameter 3, find the probability that the switch

board is over taxed in any one minute?

Construct all random samples consisting three observations from the given data. Arrange the observations in ascending order without replacement and repetition.

86 89 92 95 98

The life of a compressor manufactured by a company is known to be 200 months on an

average following an exponential distribution. Find the probability that the life of a

compressor of that company is (i) less than 200 months (ii) between 100 months to 25

years?

2000 Grade 11 students of MORMS took a Statistics test. The scores were distributed normally with a mean of 70 and Standard deviation of 5. Label the mean and three standard deviation from the mean.

1. What percentage of scores are between 65 and 75?

2. What percentage of scores are between 60 and 70?

3. What percentage of scores less than a score of 60?

4. What percentage of scores greater than a score of 80?

5. What percentage of score are between 70 and 75?