The mean systolic blood pressure for a random sample of 28 women ...

[theo]

The mean systolic blood pressure for a random sample of 28 women aged 18-24 is 115.2 mm Hg and the standard deviation is 13.1 mm Hg.
 
  Construct a 90 confidence interval for the standard deviation , of the systolic blood pressures of all women aged 18-24. Round to the nearest hundredth when necessary.
  A) (11.23, 15.99 ) B) (10.22, 18.34 ) C) (10.59, 16.54 ) D) (10.75, 16.94 )

Question 2

The time (in years) until the first critical-part failure for a certain car is exponentially distributed with a mean of 3.4 years. Find the probability that the time until the first critical-part failure is less than 1 year.
 
  A) 0.966627 B) 0.033373 C) 0.745189 D) 0.254811

[carolinefletcherr]

Answer to Question 1

D

Answer to Question 2

D