Statistics and Probability Answers

The average number of milligrams (mg) of cholesterol in a cup of a certain brand of ice cream is 660 mg, and the standard deviation is 35 mg. Assume the variable is normally distributed.

_______3. If a sample of 10 cups of ice cream is selected, what is the probability that the mean

of the sample will be larger than 670 mg?

A.   11.84%                       B. 14.18%            C. 18.41%           D. 19.41%

_______4. If a sample of 10 cups of ice cream is selected, what is the probability that the mean

of the sample will be smaller than 625 mg?

A.   0.0008%                     B. 0.008%            C. 0.08%             D. 0.8%

_______5. If a sample of 10 cups of ice cream is selected, what is the probability that the mean

of the sample will be larger than 637 mg?

A.   91.28%                       B. 98.12%            C. 98.21%           D. 99.21%

A jar contains 9 red marbles numbered 1 to 9 and 3 blue marbles numbered 1 to 3. A marble is drawn at random from the jar. Find the probability that the marble is red or even-numbered?

 A sample of 100 recorded deaths in the United States during the past year showed an average life span of 71.8 years. Assuming a population standard deviation of 8.9 years,

does this seem to indicate that the average life span today is greater than 70 years? Use a level of significance:

a. 1%

b. 5%

c. 10%

At a suburban shopping mall 70% of customers pay by ecocash.Find the probability that in a randomly selected sample of ten customers : exactly 3 pay by ecocash and more than 6 pay by ecocash

europeans have a mean paid vacation each of six weeks. what is the null and alternative hypothesis of it

P(z<1.46)

Akosua works as the customer service officer at the Agarwal Eye Clinic located in Tesano, a suburb of

the Greater Accra region. The number of requests from male patients for emergency eye treatment that

she receives during any day may be modeled by a poisson distribution with mean of 2.6.Find the

probability that the number of requests from male patients for emergency eye treatment that Akosua

receives on a particular day is;

(i) Exactly 4

(ii)At least 1

(b) Find the probability that the number of requests from male patients for emergency eye

treatment that Akosua receives during a period of 5 days is 15 or fewer

. A new machine is being considered to replace the old machine being used. This new machine was tested for 10 consecutive hours with the following output: 119, 122, 118, 122, 120, 124, 126, 125, 125, and 124. If the average output per hour using the old machine is 120 units, is the management justified in stating that the output per hour can be increased with the new machine? Use a 0.01 level of significance.

An educational researcher found that the average entrance core of the incoming freshmen in a university is 84. A random sample of 24 students from a public school was then selected and found out that their average score in the entrance exam is 88 with a standard deviation of 16. Is there any evidence to show that the sample students from public school performed better than the rest in the entrance examination using the 0.01 level of significance?