The value of z* should be used to construct a 97 confidence interval of a population mean is 2.17.
<h3>What is confidence interval?</h3>
A degree of uncertainty and certainty in a sample process is measured by confidence intervals. They can choose from a variety of probability limitations, the most frequent becoming a 95% or 99% confidence level.
Some characteristics of confidence interval are-
- Statistical tools, such as the t-test, are used to compute confidence intervals.
- Confidence intervals are used by statisticians to quantify uncertainty in such a sample variable.
- A researcher, for example, may randomly select multiple samples drawn from the same population and compute a confidence interval for every sample to determine how well it might represent the real value of a population variable.
- The generated datasets are all unique; some intervals contain the genuine population parameter while others do not.
Now, according to the question;
The confidence level is given 97%.
Thus, the crucial value of z for a 97% confidence interval is 2.17, as determined by a z score table, which is as follows:

Therefore the obtained probability for the z-score of 2.17 is 0.97.
To know more about the confidence interval, here
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The numbers are 15 and 105.
Lin thought a two digit number that is 15, if we multiply 15 with 7 , 15 x 7 = 105 that is we get Jen's number.and if we put 0 between the two digits of Lin's number, we also get Jen's number;that is 105.
We will use the Unitary method to solve this question
304/4=76
Therefore The train travels 76 miles per hour
76*7.5=570
Therefore the train travels 570 miles in 7.5 hours
Answer:
a) Between 74 and 90
b) 81.86% of the scores are between 78 and 90
Step-by-step explanation:
a) According to the Empirical Rule, in a normal distribution, 95% of the data are within 2 standard deviations of the mean. Therefore, the range that 95% of the scores fall in is between 82-4(2)=74 and 82+4(2)=90.
b) The percent of scores that are between 78 and 90 is: normalcdf(lower,upper,μ,σ) = normalcdf(78,90,82,4) = 0.8185946784 ≈ 0.8186, or about 81.86% of the scores.
If sum of numbers (a) +(b) is 1419 and
(a) and (b) are <span>neighbors , whe have:
a + b = 1419 and b-a = 1;
<=> </span>a + b = 1419 and <span>a = b-1 ;
so we have b-1 + b = 1419 <=> 2b = 1420 <=> b=710 and a = 709
Answer: 710 and 709
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