PLEASE ANSWER How many liters of a 35% salt solution must be mixed with 20 liters of 70% salt solution to obtain a solution that
1 answer:
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A stem and leaf plot is a table where each of the data is divided into two parts. The stem, that is the first digit and the leaf is the last digits. Let's say that we have the following set of data.
If we want to make a stem and leaf plot of that data, we first write a column where we place the first digit of each number without repetition, like this:
These are the stems. Now the leaves are the last digit of each number put in order next to the corresponding first digit, like this:
Answer: b. 0.98
Step-by-step explanation:
The formula to find the maximum error of the estimated mean :
(1)
, where = standard deviation
n= Sample size
z* = Critical z-value.
As per given , we have
n=100
Critical value for 95% confidence interval = z*=1.96
Put these values in the formula (1), we get
Hence, the maximum error of the estimated mean quality for a 95% level of confidence is 0.98.
Therefore , the correct answer is b. 0.98 .
Answer:
There is not enough evidence to support the claim that the amount of vitamin C in a tablet sample is different from 500 mg.
P-value = 0.166.
Step-by-step explanation:
We start by calculating the mean and standard deviation of the sample:
Then, we can perform the hypothesis t-test for the mean.
The claim is that the amount of vitamin C in a tablet sample is different from 500 mg.
Then, the null and alternative hypothesis are:
The significance level is 0.05.
The sample has a size n=5.
The sample mean is M=496.8.
As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=6.5.
The estimated standard error of the mean is computed using the formula:
Then, we can calculate the t-statistic as:
The degrees of freedom for this sample size are:
This test is a left-tailed test, with 4 degrees of freedom and t=-1.1, so the P-value for this test is calculated as (using a t-table):
As the P-value (0.166) is bigger than the significance level (0.05), the effect is not significant.
The null hypothesis failed to be rejected.
There is not enough evidence to support the claim that the amount of vitamin C in a tablet sample is different from 500 mg.