Question

The percent of fat calories that a person in America consumes each day is normally distributed with a mean of about 36 and a standard deviation of about ten. Suppose that 16 individuals are randomly chosen.

1. Find the first quartile for the percent of fat calories

A study measures blood pressure among college students. The lowest actual blood pressure is 70, and the highest is 130. Each blood pressure test is equally likely. It follows a uniform distribution. So the mean of each blood pressure test is 100 and standard deviation is 17.3205. A sample of 100 students’ blood pressure is taken.

1. What is the probability that the mean of blood pressure is less than 97.

2. Find the 90 percentile for the mean of 100 blood pressure.

A large cooperation has quality control over its fertilizers. The fertilizes are composed of nitrogen. The fertilizer requires 3 mg of nitrogen. The distribution of the percentage of nitrogen is unknown with a mean of 2.5 mg and a standard deviation of 0.1. A specialist randomly checked 100 fertilizer samples.

1. What is the probability that the mean of the sample of 100 fertilizers less than 2 mg?

A typical adult has an average IQ score of 105 with a standard deviation of 20. If 20 randomly selected adults are given an IQ test, what is the probability that the sample mean scores will between 102 and 110 points?

Answer 1

solution - LA) l= 36 10 n = 16 (1) t-score for first quastle= -0.67 = -0.67 = *-30 lo 29.3 (B) les loo - 173048 17:3205 (1) Placg 97-100.0 17 3205 V Too =P(2.6 - 1.73) - 10.0418 22) Z- scope for goth percentile = 1.28 17:3005 F-10222 1-28= F- 100 V700 ( CUP (E22) = P(2.c 2 - 25 ) Vloo - Placaro) ID) P ( 102lXello, 102-105 cal 110-105) =P(-20 1.12 =PL-0.67 czcoa) 10.6172