Answer:
a=55
Step-by-step explanation:
This question is asking for you to find the whole (a), given a part (11). This can be done through multiplication. 20% is 1/5 of 100%. This means to find the whole number, you should multiply the part by 5. 11*5=55. So, a must equal 55.
We can check this answer by working backward. Do this by finding 20% of 55, and checking to see if it is 11. To find a percentage of a number, multiply that number by the percent in decimal form. So, 20% of 55 is equal to 0.2*55, which is 11. Therefore, the answer is correct.
Answer:
martina is 22 feet below sea level
Step-by-step explanation:
Marina goes down 20 feet
then rises 7 feet which is 20 - 7 = 13
then goes down 9 more feet which is 13 + 9 = 22 feet
20 - 7 + 9 =22
Martina is 22 feet below sea level.
Answer:
Probability that the sample mean comprehensive strength exceeds 4985 psi is 0.99999.
Step-by-step explanation:
We are given that a random sample of n = 9 structural elements is tested for comprehensive strength. We know the true mean comprehensive strength μ = 5500 psi and the standard deviation is σ = 100 psi.
<u><em>Let </em></u>
<u><em> = sample mean comprehensive strength</em></u>
The z-score probability distribution for sample mean is given by;
Z =
~ N(0,1)
where,
= population mean comprehensive strength = 5500 psi
= standard deviation = 100 psi
The Z-score measures how many standard deviations the measure is away from the mean. After finding the Z-score, we look at the z-score table and find the p-value (area) associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X.
Now, Probability that the sample mean comprehensive strength exceeds 4985 psi is given by = P(
> 4985 psi)
P(
> 4985 psi) = P(
>
) = P(Z > -15.45) = P(Z < 15.45)
= <u>0.99999</u>
<em>Since in the z table the highest critical value of x for which a probability area is given is x = 4.40 which is 0.99999, so we assume that our required probability will be equal to 0.99999.</em>
Answer:

Step-by-step explanation:
There are

different ways to select the four numbers between 1 and 42. Only one of this ways is correct (successful to win).
There are 30 different ways select the single number between 1 and 30. Only one of them is correct.
The probability of winning the jackpot is
