('I point} The National Institute of Standards and Technology [HIST] supplies "standard materials" whose physical properties are supposed to be known. For example. you can buy from HIST a liquid whose electrtcal conductivity is supposed to be 5. [The units for conductivity are microsiemens per centimeter. Distilled water has conductivity (1.5.) Of course. no measurement is exactly correct. MIST knows the variability of its measurements very well, so it is quite realistic to assume that the population of all measurements of the same liquid has the Normal distribution with mean p equal to the true conductivity and standard deviation 0' = [1.2. Here are 6 measurements on the same standard liquid. which is supposed to have conductivity 5: 5.32 4.88 5.10 4.?3 5.15 4.?5 NIST wants to give the buyer of this liquid a 90% condence interval for its tme conductivity. What Is this Interval? ID to [J ( 1 point ; Here are the IQ test scores of 31 seventh- grade girls in a Midwest school district . 1 1 4 100 104 89 102 91 1 1 4 1 1 4 1 03 105 108 130 120 1.32 1 1 1 128 1 18 1 19 86 72 1 1 1 103 74 1 12 1 07 103 98 96 1 12 1 12 93 These 31 girls are an SAIS Of all seventh - grade girls in the school district . Suppose that the standard deviation of IQ scores in this sulation is known to be ` = 15 . We expect the distribution of IQ scores to be close to Normal . Estimate the mean IQ score for all seventh - grade girls in the school district , using a 98%'6 confidence interval . to