Answer:
The mean number of adults who would have bank savings accounts is 32.
Step-by-step explanation:
For each adult surveyed, there are only two possible outcomes. Either they have bank savings accounts, or they do not. So we use the binomial probability distribution to solve this problem.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:

In this problem, we have that:

If we were to survey 50 randomly selected adults, find the mean number of adults who would have bank savings accounts.
This is E(X) when
.
So

The mean number of adults who would have bank savings accounts is 32.
99.7% encompasses about 3 standard deviations either side of the mean.
82 ±3*2 = (76, 88)
About 99.7% of the values lie between 76 and 88.
Answer:
I THINK its the last one (8 root 10 to the power of 3x)
Step-by-step explanation:
A square root is the same thing as raising something to the 1/2. So the expression we have is (10^1/2)^3/4x.
Due to exponent rules we can multiply to get
10^3/8x which is the same thing as 10^3x/8
The 8 goes to the root and the 3x becomes the exponent
1. x = 15120/12 = 1260 (monthly salary)
2. 1200 x 0.05 = 60 (raise)
Check: 1200+60=1260
Answer:
269
Step-by-step explanation:
The margin of Error is E = 0.05
The level of significance is, α = 1 - confidence level = 1 - 0.9 = 0.1
Assume that the proportion is, p =0.5
From the standard normal table, observe that the critical value of Z for two tail test and 10% level of significance is 1.64
The calculation of sample size is as follows: n = (Z/E)²p(1-p)
n = (1.64/0.05)²0.5 (1 - 0.5)
n = (1.64/0.05)² 0.25
n = 1075.84 × 0.25
n = 268.96 ≈ 269
The required sample size with the given margin of error approximately is 269. This value indicates the size of the customers who are using this company’s products.