Answer:

Step-by-step explanation:
Given
The attached triangle
Required
Find y
The attached triangle is isosceles; so:

Also, we have:
--- angles in a triangle
Substitute: 

Collect like terms


Answer:
selecting one item? If you mean each color:
40% chance for a red marble / 2/5 chance
60% chance for a blue marble / 3/5 chance
Step-by-step explanation:
Because there are 12 blue marbles and 8 red marbles, we would total them to see how many marbles there are in total. There are 20 in total, but to find the probability, if we put all 20 marbles in a bag (blue and red), and we picked a marble at random, there are 8 red marbles and 12 blue marble in that bag. The probability that I will choose red marbles is 8/20 (or 8 red marbles out of 20 total marbles), and for blue marbles, it would be 12/20 (or 12 blue marbles out of 20 total marbles). Simplify both expression to 2/5, and 3/5 respectively. Finally, if you need percentage, just multiply the denominator by 5 to get it to a hundred, and do the same to the numerator. This way you don't change the value of the expression.
Answer:
0.61
Step-by-step explanation:
Pr (female) = total number of females(n')/Total number of students(n)
Where P(female) = probability of selectinga female
Pr(female) = n'/n................. Equation 1
Given: n = 44 students, n' = 15+12 = 27 females
Substitute into equation 1
Pr(female) = 27/44
Pr(female) = 0.61.
Hence the probability of selecting a female is 0.61
Answer:
The 99% confidence interval is
Step-by-step explanation:
From the question we are told that
The sample size is n = 100
The sample mean is 
The population standard deviation is
From the question we are told the confidence level is 99% , hence the level of significance is
=>
Generally from the normal distribution table the critical value of
is
Generally the margin of error is mathematically represented as

=>
Generally 95% confidence interval is mathematically represented as
=>
=>
Answer:
180 - 90 = 90
half of 90 = 45
40 and 50??
Step-by-step explanation: