The mean weight of adult males is 165 pounds with a standard deviation of 30 pounds. if a sample of 35 adult males is selected, find the probability that the mean of the sample will be less than 155 pounds

0.5244 is the answer.

Step-by-step explanation:

Given that  the mean weight of males adult is 165 pounds.

Std deviation is 30 pounds

Sample size n = 35

Hence sample std deviation = 30/sq rt 35 = 5.071

Then X bar the mean of the sample follows a normal distribution

X bar : N(165, 5.071) by central limit theorem

Required probability =P(X<155)

When x =155, Z =

Hence P(X<155) = P(Z<-1.972) = 0.5-0.4756

= 0.5244

b

step-by-step explanation:

given

- 2 (3x + 12y - 5 - 17x - 16y + 4 )

simplify the parenthesis by collecting like terms

= - 2 (- 14x - 4y - 1) ← distribute the parenthesis by - 2

= 28x + 8y + 2 → b

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500