Answer:
Step-by-step explanation:
information given
represent the sample mean
represent the population standard deviation
sample size
represent the value that we want to test
represent the significance level for the hypothesis test.
z would represent the statistic
represent the p value for the test
Hypothesis to test
We want to test if the true mean is less than 12, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
The statistic is given by:
(1)
Replacing the info given we got:
We can replace in formula (1) the info given like this:
Answer:
Step-by-step explanation:
((95.26 - 78.17) / 78.17)x100
21.86260714% percentage decrease
The phone call was worth his time
Answer:
Q6. D
Q8. A
Step-by-step explanation:
Q6. In 40 trials, he flipped '2 heads and 1 tail' 16 times.
For 2 heads, probability= 16/40= 4/10
For 120 trials, number of times= 4/10 × 120= 48
Q8.

Answer is A because the inequality shows that x is equal or greater than 8 so the dot at 8 has to be coloured.
Note that we do not change the inequality sign unless we are dividing the whole thing by -1.
Answer:
The answer would be (1.23, 4.39)
Step-by-step explanation:
Because they are both equal to y, we can set the equations equal to each other and then solve.
4.9x - 1.64 = -0.25x + 4.7
5.15x - 1.64 = 4.7
5.15x = 6.34
x = 1.23
Now that we have the value for x, we can plug into either equation and find y.
y = -0.25x + 4.7
y = -0.25(1.23) + 4.7
y = -.31 + 4.7
y = 4.39
Im not sure if you need to find the area or de expression of how to find the AREA. but what you do if explain how you can find it by multiplying that will be 4.. and then also 4? Im not sure but you can try