Answer: 
Step-by-step explanation:
The confidence interval for population mean is given by :-

Given : Sample size : n= 35 , large sample (n>30)
Mean difference : 
Standard deviation : 
Significance level : 
Critical value : 
Now, the 99.9% confidence interval for the mean difference between the marks scored last week and marks scored this week by all the students will be :-

Hence, the 99.9% confidence interval for the mean difference between the marks scored last week and marks scored this week by all the students = 
I believe its 31/100! <span>To write 0.3111 as a fraction you have to write 0.3111 as numerator and put 1 as the denominator. Now you multiply numerator and denominator by 10 as long as you get in numerator the whole number.</span>
Answer:
1) The size of the colony after 4 days is 6553 mosquitoes
2) After
Step-by-step explanation:
To answer this question you must use the growth formula

Where
is the initial population of mosquitoes = 1000
t is the time in days
k is the growth rate
N is the population according to the number of days
We know that when t = 1 and
then N = 1600
Then we use these values to find k.

Now that we know k we can find the size of the colony after 4 days.

To know how long it should take for the population to reach 10,000 mosquitoes we must do N = 10000 and solve for t.

Answer:
2.275%
Step-by-step explanation:
The first thing to do here is to calculate the z-score
Mathematically;
z-score = (x-mean)/SD
from the question, x = 12,300 hours , mean = 11,500 hours while Standard deviation(SD) = 400 hours
Plugging the values we have;
z-score = (12,300-11,500)/400 = 800/400 = 2
Now, we want to calculate P(z ≤ 2)
This is so because we are calculating within a particular value
To calculate this, we use the z-score table.
Mathematically;
P(z ≤ 2) = 1 - P(z > 2) = 1 - 0.97725 = 0.02275
To percentage = 2.275%
In the given question, there are several data of immense importance. based on these data's the answer to the question can be easily deduced. it is already given that the total utility bill for the month of April in Millers house is $132 and 42% of the bill was paid for gas. remaining amount is paid as electricity charges.
Now
Amount of money paid for gas = 132 * (42/100) dollars
= 5544/100 dollars
= 55.44 dollars
Then
The amount of money paid for electricity = (132 - 55.44) dollars
= 76.56 dollars
So the Millers paid 55.44 dollars for gas and 76.56 dollars for electricity in the month of April.