Answer:
We need a sample size of at least 719
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
So it is z with a pvalue of 
, so 
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
How large a sample size is required to vary population mean within 0.30 seat of the sample mean with 95% confidence interval?
This is at least n, in which n is found when 
. So
Rouding up
We need a sample size of at least 719
Answer:
rational
Step-by-step explanation:
irrational numbers can not be expressed as a fraction
15500 times 0.37 is 5735.
$5735
The 11% statement is extra information.
Answer:
The percentage increase in the cost of Boris car insurance cost is 249%
Step-by-step explanation:
In this question, we want to calculate the percentage increase in the cost of car insurance paid by Boris
Mathematically, to calculate this percentage increase, we shall need to make use of a mathematical formula.
Mathematically, the percentage increase would be;
{(new value paid-old value paid)/old value paid} * 100%
From the question, we can identify that the old value paid is £256 while the new value paid is £894
Thus, the percentage increase would be ;
(894-256)/256 * 100% = 638/256 * 100 = 2.4921875 * 100 = 249.21875 which is 249% increase to the nearest whole percentage
Answer:c
Step-by-step explanation:
