Answer:
Bella can complete work alone in 120 minutes
Step-by-step explanation:
Ana and Bella together can complete the shoveling in 30 minutes.
They can do a part of work in 1 minute = 
Ana can do work alone in 40 minutes
She can do part of work in 1 minute = 
So, Bella can do a part of work in 1 minute = 
= 
Bella can do
part of work in 1 minute
Bella can do whole work in minutes = 120
Hence Bella can complete work alone in 120 minutes
Answer:
x=8
Step-by-step explanation:
Answer:
that is a very good question sir
Step-by-step explanation:
Answer:
The mean of the sampling distribution of the sample proportions is 0.82 and the standard deviation is 0.0256.
Step-by-step explanation:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean
and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For proportions, the mean is
and the standard deviation is 
In this problem, we have that:
.
So


The mean of the sampling distribution of the sample proportions is 0.82 and the standard deviation is 0.0256.

Scientific notation for above vLue is :