Search & Filtering
If cos(π ) = 3/5 and tan( π ) < 0 , find the exact value of each of the remaining trigonometric functions of π
A lawyer claims that the average years of settling criminal cases filed before courts is three
and a half years. To test the claim, a watchdog organization randomly selected 35 criminal
cases and recorded the years the cases took before the courts have been rendered verdicts.
The sample mean was 4 years with a standard deviation of three and a half years. Do the
data gathered by the said organization provide sufficient basis to accept the claim of the
lawyer? Use 0.05 level of significance.
A company claimed that their N95 face mask has a mean filtration efficiency rate of
95%. A group of student researcher wanted to verify this claim. They bought and tested
40 of their N95 face masks. They found out that the average filtration efficiency rate of
these face mask was 90% with a standard deviation of 4%. Test the claim at 5% level
of significance and assume that the population is approximately normally distributed.
A survey unofficially claimed that in every five young executives, only one practices good reading habits.
a. What is the probability that out of 10 young executives, two executives practice good reading habits?
b. What is the probability that at least five out of 20 young executives practice good reading habits?
the following data were obtained by sampling a population
5
3
7
5
6
8
6
5
9
Compute for the mean.
For some electronic component , the time until failure has Gamma distribution with parameter a= 2 and y= 3( years ^-1). Compute the probability that component fails within the first 6 months.
A population has mean 75 and standard deviation 12.
a.)Random samples of size 121 are taken. Find the mean and standard deviation of sampling distribution of the means?
b.)How would the answers to part (a) change if the size of the samples were 400 instead of 121?
How many ways are there to select 12 countries in the United Nations to serve on a council if 2 is selected from a block of 55, 2 are selected from a block of 67 and 8 are selected from the remaining 67 countries
(a)Β Β The operations manager of a company that manufactures tires wants to determine whether there are any differences in the quality of work among the three daily shifts. She randomly selects 496 tires and carefully inspects them. Each tire is either classified as perfect, satisfactory, or defective, and the shift that produced it is also recorded. The two categorical variables of interest are the shift and condition of the tire produced. The shift quality data can be summarized by the accompanying two-way chi-square table as shown below. Does the data provide sufficient evidence at the 5% significance level to infer that there are differences in quality among the three shifts?
Type of shift
Perfect
Satisfaction
Defective
Total
Shift 1
106
124
1
231
Shift 2
67
85
1
153
Shift 3
37
72
3
112
Total
210
281
5
496
find the class boundaries, midpoint, and width for the class 12.4-15.2
