An article presents measures of penetration resistance for a certain fine-grained soil. fifteen measurements, expressed as a multiple of a standard quantity, had a mean of 2.64 and a standard deviation of 1.06. find a 95% confidence interval for the mean penetration resistance for this soil. round the answers to three decimal places.

[2.053 , 3.227]

Step-by-step explanation:

The 95% confidence interval is given by the interval

where

= the sample mean  

s = the sample standard deviation  

n  = the sample size

is the 0.05 (5%) upper critical value for the Student's t-distribution with 14 degrees of freedom (sample size -1), which is an approximation to the Normal distribution for small samples (n<30).

Either by using a table or the computer, we find  

and our 95% confidence interval is

the inequality is:

250c+180g≥950

step-by-step explanation:

let c denotes the number of days in a week   miyoko worked as a cryptographer.

and g denotes the number of days in a week she works as a geologist.

now we are given that she earns $250 for every day she works as a cryptographer,and earns $180 for every day she works as a geologist.

now miyoko's goal is to earn more than $950 this week.

hence, the inequality could be represented as:

250c+180g≥950

i believe your answer is 99.7% of 7-year-old children are between 46.6 inches and 49.5 inches tall.