Exhibit 15-2a regression model between sales (y in $1000s), unit price (x1 in dollars) and television advertisement (x2 in dollars) resulted in the following function: ŷ = 7 − 3x1 + 5x2for this model, ssr = 3500, sse = 1500, and the sample size is 18.the coefficient of x2 indicates that if television advertising is increased by $1 (holding the unit price constant), sales are expected to

Sales are expected to increase positively.

Step-by-step explanation:

The model is y =7-3*X1+5*X2

Here, y is the depended variable and X1 and X2 are independent variable.  

Holding the unit price constant X2 (television advertisement) is increase by $1 dollar

SSR= 3500

SSE=1500

So, TSS = SSR+SSE = (3500+1500) = 5000

Now r^2= 1 - (SSR/TSS) = 1 - (3,500/5,000) = 1 - 0.70 = 0.30

So, the sample correlation coefficient (r) = (0.3)^(1/2) = 0.547

We can conclude that sample correlation indicates a strong positive relationship.

you never say the total so we cant find the percentage used for petrol

step-by-step explanation:

2 & 7

step-by-step explanation:

he climbs 300 ft/hr at a constant rate. the peak is at 1,500 ft.

when going up, he reaches 600 ft in 2 hours. remember, that he is going in a constant rate. divide 600 with 300:

600/300 = 2

assuming that he takes the same route back (meaning that it's a 1500 ft route back, you can solve.

note also that you are solving when he gets back to 600 ft after he reaches the peak.

first, find the amount of hours it takes to get up the peak. divide the total amount (1500), with the ft/her (300) to get the amount of hours (x):

1500/300 = x

x = 5

it takes jamie 5 hours to get up. now, he is returning down, and reaches 600 (his current destination). remember that he climbs at a constant 300 ft/hr. divide 600 with 300:

600/300 = x

x = 2

now add the two numbers together.

x = 5 + 2 = 7

jamie takes 7 hours to go up the mountain and reach his current position when descending.

(total amount/constant rate) = (time).

remember that it is a constant rate, so in total, when he gets back down the mountain, it will take the same amount of time as when he goes up. the total amount for the round trip is: 5 + 5 = 10.

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