Statistics and Probability Answers

Complete the table below.

Type of Test n df Confidence level a t-value

1. one-tailed 12 95%

2. one-tailed 15 95%

3. two-tailed 21 99%

4. two-tailed 23 95%

5. one-tailed 25 90%

6. two-tailed 16 90%

7. one-tailed 9 95%

8. two-tailed 27 99%

9. one-tailed 18 90%

10. two-tailed 20 99%

Suppose that the average number of cars abandoned weekly on a certain highway is2.2.

Approximate the probability that there will be:

(a) no abandoned cars in the next week;

(b) at least 2 abandoned cars in the next week. . . " .....

(c) State the key assumptions needed to' make your answers in a) and b) reasonable

Fundamental Principle of counting

You want to put your wattpad in bookshelf. In how many ways can the 7 wattpad be arrange in the shelf?

manager of a courier service believes that packets delivered at the end of the month are heavier than those delivered early in the month. As an experiment, he weighed a random sample of 20 packets at the beginning of the month. He found that the mean weight was 5.25 kgs with a standard deviation of 1.20 kgs. Ten packets randomly selected at the end of the month had a mean weight of 4.96 kgs and a standard deviation of 1.15 kgs. At the 0.05 significance level, can it be concluded that the packets delivered at the end of the month weigh more?

In the daily production of a certain kind of rope, the number of defects per foot

Y is assumed to have a Poisson distribution with mean A = 2. The profit per foot

when the rope is sold is given by X, where X = 50 - 2Y - y2. Find the expected

profit per foot

Assume that the daily S&P return follows the normal distribution with mean μ = 0.00032 and standard deviation a= 0.00859.

a. Find the 75th percentile of this distribution.

b. Find the probability that the daily S & P return will be larger than 0 01

C. Consider the sample average S & P of a random sample of 20 days.

27:2 i. Describe the distribution of the sample mean with its expected value and standard error.

ii. What sample size is necessary to double the standard error of the mean?

iii. Is it more likely that the average S & P will be greater than 0 007, or that one day's S & P return will be?

iv. Find the number b such that P(x > b) = 0975

in a graduate college,the average lenght of registration time during a semester is 120 minutes with a standard deviation of 25 minutes .with the introduction of a new registration procedure,a random sample of 50 students system took an average of 80 minutes sith a standard devation of 12 minutes

The average length of time for students to enroll in college is 6 hours and 10 minutes. Computerized enrolment is being tested. In a random sample of 180 students, it was found out that the average time for them to enroll is 2 hours and 45 minutes with a standard deviation of 20 minutes. At = 0.01, does this indicate that the average time for students to enroll using computerized enrolment is less than the regular enrolment?

A new drug on the market is claimed by its manufacturers to reduce overweight women by 4.55 kg per month with standard deviation of 0.91 kg. Ten women chosen at random have reported losing an average of 4.05 kg within a month. Does this data support the claim of the manufacturer at 0.05 level of significance?

A new drug on the market is claimed by its manufacturers to reduce overweight women by 4.55 kg per month with standard deviation of 0.91 kg. Ten women chosen at random have reported losing an average of 4.05 kg within a month. Does this data support the claim of the manufacturer at 0.05 level of significance?