Given two dependent random samples with the following results: Population 1 30 35 23 22 28 39 21 Population 2 45 49 15 34 20 49 36 Use this data to find the 90% confidence interval for the true difference between the population means. Assume that both populations are normally distributed. Step 1 of 4: Find the point estimate for the population mean of the paired differences. Let x1 be the value from Population 1 and x2 be the value from Population 2 and use the formula d=x2−x1 to calculate the paired differences. Round your answer to one decimal place.

(-14.8504 ; 0.5644)

Step-by-step explanation:

Given the data:

Population 1 : 30 35 23 22 28 39 21

Population 2: 45 49 15 34 20 49 36

The difference, d = population 1 - population 2

d = -15, -14, 8, -12, 8, -10, -15

The confidence interval, C. I ;

C.I = dbar ± tα/2 * Sd/√n

n = 7

dbar = Σd/ n = - 7.143

Sd = standard deviation of d = 10.495 (using calculator)

tα/2 ; df = 7 - 1 = 6

t(0.10/2,6) = 1.943

Hence,

C.I = - 7.143 ± 1.943 * (10.495/√7)

C.I = - 7.143 ± 7.7074

(-14.8504 ; 0.5644)

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation: