Statistics and Probability Answers

Dawn Corporation has 12 employees who hold managerial positions. Of them, 7 are female and 5 are male. The company is planning to send 3 of these 12 managers to a conference. If 3 managers are randomly selected out of 12, Find the probability that at most 2 of them are female.

Suppose you are working for a company in the music business. They make stereos, musical instruments and produce CD’s. They decide to do a survey on dance preferences by college students. Basically, they wanted to know about college students’ interests and practices on dance music. A survey was administered to a random sample of 37 students and recorded in Table 1:
A – Ironic dance B – Pro dance C – Sway dance
D – Dad-dance E – Twerk dance




Male Female Male Female Male
A A A A E
C E C C A
A A C B E
A C A D D
A A B A A
C D E B B
D A D D A
D A
Based on Table 1 in Question 1:
a) Prepare a multiple frequency table for dance preferences of both genders.
b) Using your frequency table, draw a multiple bar chart to represent the information.
c) Briefly discuss and compare the percentage of favorite and least favorite dance preferences of both genders.

In a project involving skinfold thickness measurements is three groups, a Levene statistic was reported at 3.286 with a significance of 0.68. Is the assumption of homogeneity of variance met for this ANOVA?
1.yes
2. No
3.cant tell

1. Suppose X and Y are independent continuous random variables. Show that
E[X|Y = y] = E[X] for all y

2. The joint density of X and Y is
f (x, y) = (y^2 − x^ 2) * e^(−y), 0 < y < ∞, −y <= x <= y
Show that E[X|Y = y] = 0.

minimum credit hours taken by an it student per semester is normal with mean of 12 credit hours and standard deviation of 3.5 credit hours. the registrar office wishes to establish a credit hours value c beyond which there will be penalty charge. what value of c is such that 99% of all students are at least 1 credit hour under the penalty charge?

A manufacturer of guitar amplifiers markets one of its models, Vagabond, at a power rating of 45 watts. GuitarGod magazine suspects that this rating is inaccurate for this year's model of the amp. In a random sample of 32 units of this year's version of the Vagabond the mean output power is 42 watts, with a standard deviation of 8 watts.

Assuming a confidence level of 95%, which of the following statements do these data support?


A. This year's Vagabond's output power is 45 watts.
B. This year's Vagabond's output power is 42 watts.
C. This year's Vagabond's output power is not 45.
D. None of the above

Table 1

Male Female Male Female Male
A A A A E
C E C C A
A A C B E
A C A D D
A A B A A
C D E B B
D A D D A
D A

A survey was administered to a random sample of 37 students and recorded in Table 1:

A – Ironic dance B – Pro dance C – Sway dance
D – Dad-dance E – Twerk dance


Prepare a summary table for dance preferences. Calculate percentage and sectarian angle of each type of dance preferred. Represent these figures on a pie chart. Draw a bar chart to represent the dance preferences.

A bag contains 3 black balls and 5 white balls. Samuel picks a ball at random from the bag and replaces it back in the bag. He mixes the balls in the bag and then picks another ball at random from the bag. Construct a probability tree of the problem and calculate the probability that Samuel picks two black balls and a black ball in his second draw.

Table 1
18 15 17 22 12 20
19 15 20 25 16 13

Calculate the mean, the median, the mode, the standard deviation, the Pearson coefficient of skewness of assembling time.

what does that symbol stand for ф