Answer:
5 marbles
Step-by-step explanation:
A bag contains
8 white marbles
6 red marbles
4 blue marbles.
Total number of marbles is :
8 + 6 + 4
= 18 marbles
Based on this current proportion
The Probability of choosing a blue marble = Number of blue marbles/ Total number of marbles
In order for the Probability of choosing a blue marble to be 1/2
The number of blue marbles has to be:
= 18 marbles × 1/2
= 9 blue marbles
From the question we have 4 blue marbles, hence:
9 blue marbles - 4 blue marbles
= 5 blue marbles
Therefore, 5 blue marbles must be added to the bag so that the probability of choosing a blue marble is 1/2.
Ava's sister paid a 4.5% annual interest rate
Her sister paid $54 more than she borrowed, divide that by 3 (years till she paid)
54/3 = 18
That's $18 for every year she'd had the $400 loan out, divide it by 4 to get the percentage
18/4 = 4.5/100 = 4.5%
Answer:
The answer is 4
Step-by-step explanation:
The reason for is that it says 16 is 4 it’s simple .
Answer: 13
Step-by-step explanation:
cost for 3 hours: 7+2(3)=13
cost for t hours: 7+2t
Answer:
The 99% confidence interval for the fraction of U.S. adult Twitter users who get some news on Twitter is between 49.34% and 60.66%, which means that we are 99% sure that the true percentage of US adult Twitter users who get some news is in this interval.
Step-by-step explanation:
Confidence interval:
A confidence interval has the following format:
![M \pm zs](https://tex.z-dn.net/?f=M%20%5Cpm%20zs)
In which M is the sample mean, z is related to the confidence level and s is the standard error.
55% of U.S. adult Twitter users get at least some news on Twitter (Pew, 2013). The standard error for this estimate was 2.2%.
This means that ![M = 55, s = 2.2](https://tex.z-dn.net/?f=M%20%3D%2055%2C%20s%20%3D%202.2)
99% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
Lower bound of the interval:
Upper bound:
The 99% confidence interval for the fraction of U.S. adult Twitter users who get some news on Twitter is between 49.34% and 60.66%, which means that we are 99% sure that the true percentage of US adult Twitter users who get some news is in this interval.