Answer:




Step-by-step explanation:
Given
close
fail to close


First, calculate the value of q
Using complement rule



So, we have:
and 
Solving (a): Fails to close on the 4th attempt
This means that he closes the first three attempts. The event is represented as: p p p q
So, we have:




Solving (b): He closes for the first time on the 3rd attempt
This means that he fails to close the first two attempts. The event is represented as: q q p
So, we have:




Solving (c): First he closes is his 2nd attempt
This means that he fails to close the first. The event is represented as: q p
So, we have:



Solving (d): The first he close is one of his 3 attempts
To do this, we make use of complement rule
The event that he does not close any of his first three attempts is: q q q
The probability is:


The opposite is that the first he closes is one of the first three
So, we have:
--- complement rule




Answer:
A diagonal. (A rectangle is divided into two triangles by a diagonal, for example.)
Answer: u= ( 4342.08, 5145.92).
Step-by-step explanation: the population mean is estimated using the sample by the formulae assuming a 95% confidence level
u = x' + Zα/2 * (√σ/n) or x' - Zα/2 * (√σ/n)
u = estimated population mean
x' = sample mean = 4744
n = sample size =8
σ = sample standard deviation. = 580
α = level of significance = 1- confidence level = 1-0.95= 0.05
Zα/2 = z score from the normal distribution table for a 2 tailed test = 1.96
First boundary value for interval
u = 4744 + 1.96 ( 580/√8)
u = 4744 + 1.96 * (205.0609)
u = 4744 + 401.92
u = 5145.92
Second boundary value for interval
u = 4744 - 1.96 ( 580/√8)
u = 4744 - 1.96 * (205.0609)
u = 4744 - 401.92
u = 4342.08
Thus the confidence interval for population mean is
u= ( 4342.08, 5145.92).
Answer:
Step-by-step explanation:
45 times 7= 315
326-315=11
125 times 2=250
250+11=261
so the answer is C. $261