Answer:
Pure water =74.1 mL
Step-by-step explanation:
You need 420 mL of a 70% alcohol solution.
420 mL of solution and 70% of it should be alcohol.
So,
420 * 70/100 mL
= 420 * 0.7
= 294 mL of alcohol and the rest should be water.
On hand, you have a 85% alcohol mixture.
The alcohol can only come from the 85% mixture. So, how much of 85% alcohol do we need to get 294 mL of alcohol:
Let
y = alcohol solution needed
85% of y = 294
85/100 * y = 294
y = 294 ÷ 85/100
y = 294 × 100/85
y = 29,400/85
y = 345.88235294117
Approximately, 345.9mL
The rest of 420 mL solution has to be pure water
Pure water = 420 mL - 345.9mL
= 74.1 mL
Pure water =74.1 mL
Answer:
The pvalue of 0.0113 < 0.05 means that there is sufficient evidence to conclude that the mean time to find another position is less than 28 weeks at the 5% level of significance
Step-by-step explanation:
The null hypothesis is:

The alternate hypotesis is:

The test statistic is:

In which X is the sample mean,
is the value tested at the null hypothesis,
is the standard deviation and n is the size of the sample.
A recent survey of 50 executives who were laid off during a recent recession revealed it took a mean of 26 weeks for them to find another position.
This means that 
Assume the population standard deviation is 6.2 weeks.
This means that 
Does the data provide sufficient evidence to conclude that the mean time to find another position is less than 28 weeks at the 5% level of significance
We have to find the pvalue of Z, looking at the z-table, when
. It if is lower than 0.05, it provides evidence.



has a pvalue of 0.0113 < 0.05.
The pvalue of 0.0113 < 0.05 means that there is sufficient evidence to conclude that the mean time to find another position is less than 28 weeks at the 5% level of significance
What is the interquartile range for this data set? 9, 17, 3, 26, 9, 15, 7, 20, 5, 12, 22
stepan [7]
23 because you subtract your highest number with your lowest number
Answer:
4v^2-25
Step-by-step explanation:
(2v+5)(2v-5)
Using (a-b)(a+b)=a^2-b^2, simplify the product
(2v)^2-5^2
To raise a <u>product to a power</u>, raise each factor to that power.
4v^2-5^2
Evaluate the <u>power.</u>
4v^2-25