Answer: 2 tokens.
Step-by-step explanation:
From the question, we are informed that a bag contains green tokens and black tokens and that there are 8 green tokens in the bag.
We are further told that the ratio of green tokens to black tokens is 4 for every 1.
Since the green tokens is 4× the black tokens, therefore the number of black tokens in the bag will be:
= 8/4
= 2 tokens
Answer:
a) E(X)=1
b) σ=1
c) P(X>1)=0.368
d) P(2<X<5)=0.128
Step-by-step explanation:
We have X: "the time between two successive arrivals at the drive-up window of a local bank", exponentially distributed with λ = 1.
a) We have to compute the expected time between two successive arrivals.
The expected value for X as it is exponentially distributed is:

b) We have to compute the standard deviation of X.
The standard deviation is calculated as:

c) The probability that X is larger than 1 (P(X>1))
We can express the probability as:

d) The probability that X is between 2 and 5 (P(2<X<5))

Answer:
your answer will be letter B
Step-by-step explanation:
Answer:
$2,400
Step-by-step explanation:
Ken intends to start a savings account
10% = leisure spending
This means 90% = Expenses for school
Let us represent the amount he must save as : x
Hence in other for him to have $2,160 in his savings account, the amount Ken must earn is calculated as:
90/100 × x = $2,160
Cross Multiply
90x = $2,160 × 100
x = ($2,160 × 100) ÷ 90
x =$2,400
Therefore, the amount Ken has to earn to have the amount needed for school is $2,400