(a) Average time to get to school
Average time (minutes) = Summation of the two means = mean time to walk to bus stop + mean time for the bust to get to school = 8+20 = 28 minutes
(b) Standard deviation of the whole trip to school
Standard deviation for the whole trip = Sqrt (Summation of variances)
Variance = Standard deviation ^2
Therefore,
Standard deviation for the whole trip = Sqrt (2^2+4^2) = Sqrt (20) = 4.47 minutes
(c) Probability that it will take more than 30 minutes to get to school
P(x>30) = 1-P(x=30)
Z(x=30) = (mean-30)/SD = (28-30)/4.47 ≈ -0.45
Now, P(x=30) = P(Z=-0.45) = 0.3264
Therefore,
P(X>30) = 1-P(X=30) = 1-0.3264 = 0.6736 = 67.36%
With actual average time to walk to the bus stop being 10 minutes;
(d) Average time to get to school
Actual average time to get to school = 10+20 = 30 minutes
(e) Standard deviation to get to school
Actual standard deviation = Previous standard deviation = 4.47 minutes. This is due to the fact that there are no changes with individual standard deviations.
(f) Probability that it will take more than 30 minutes to get to school
Z(x=30) = (mean - 30)/Sd = (30-30)/4.47 = 0/4.47 = 0
From Z table, P(x=30) = 0.5
And therefore, P(x>30) = 1- P(X=30) = 1- P(Z=0.0) = 1-0.5 = 0.5 = 50%
What you would do is take the denominators and multiply them by each other, then multiply the numerators by that same number. So like 4/10 and 4/9. You would say, (denominators) 10x9=90 and (numerators) 4x9=36. So your first fraction would be 36/90. Next, you would take (denominators) 9x10=90 and (numerators) 4x10=40. So your second fraction would become 40/90. Now it's a lot easier to compare. 36/90 < 40/90 would be the answer to my problem. I hope I helped!
Answer:
y + 5 > -2 i.e. option 4.
Step-by-step explanation:
An inequality is shown in the number line by an arrow and we have to identify the inequality from the options given.
It is clear from the given figure that the y variable is plotted and its value is greater than - 7 but not including - 7.
Therefore, option 4 which gives the inequality y + 5 > -2 will be the correct answer.
As it gives y > - 2 - 5 i.e. y > - 7 (Answer)
Answer:
4% of all adults go to a health club at least twice a week
Step-by-step explanation:
- the proportion of adults who belong to health clubs is 10% that is 0.10
- the proportion of these adults (health club members) go to the club at least twice a week is 40%, that is 0.40.
Thus, the proportion of all adults go to a health club at least twice a week is
0.10 × 0.40 = 0.04, that is 4%
Answer:
The plumbers cost would be equal to the equation 80+45x=y with y being the total amount of money he made and x being how many hours he worked.
Step-by-step explanation:
In this equation to find the amount the plumber was paid all you need to do is plug in the amount of hours he worked for x.
If the plumber worked his maximum of 8 hours then the equation would change from 80+45x=y to 80+(45×8)=440.
So, if the plumber worked for 8 hours he would make $440.